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Ducommun Inc./DE – ‘10-K’ for 12/31/21 – ‘EX-101.LAB’

On:  Wednesday, 2/23/22, at 4:24pm ET   ·   For:  12/31/21   ·   Accession #:  1628280-22-3518   ·   File #:  1-08174

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  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/23/22  Ducommun Inc./DE                  10-K       12/31/21  111:13M                                    Workiva Inc Wde… FA01/FA

Annual Report   —   Form 10-K

Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-K        Annual Report                                       HTML   1.44M 
 2: EX-10.24    Material Contract                                   HTML     76K 
 3: EX-21       Subsidiaries List                                   HTML     33K 
 4: EX-23       Consent of Expert or Counsel                        HTML     30K 
 5: EX-31.1     Certification -- §302 - SOA'02                      HTML     34K 
 6: EX-31.2     Certification -- §302 - SOA'02                      HTML     34K 
 7: EX-32       Certification -- §906 - SOA'02                      HTML     34K 
13: R1          Cover Page                                          HTML     94K 
14: R2          Audit Information                                   HTML     35K 
15: R3          Consolidated Balance Sheets                         HTML    143K 
16: R4          Consolidated Balance Sheets (Parenthetical)         HTML     41K 
17: R5          Consolidated Statements of Income                   HTML    105K 
18: R6          Consolidated Statements of Comprehensive Income     HTML     62K 
19: R7          Consolidated Statements of Comprehensive Income     HTML     37K 
                (Parenthetical)                                                  
20: R8          Consolidated Statements of Changes in               HTML    100K 
                Shareholders' Equity                                             
21: R9          Consolidated Statements of Cash Flows               HTML    136K 
22: R10         Summary of Significant Accounting Policies          HTML    151K 
23: R11         Business Combinations                               HTML     51K 
24: R12         Inventories                                         HTML     38K 
25: R13         Property and Equipment, Net                         HTML     46K 
26: R14         Leases                                              HTML    115K 
27: R15         Goodwill and Other Intangible Assets                HTML    111K 
28: R16         Accrued and Other Liabilities                       HTML     38K 
29: R17         Long-Term Debt                                      HTML     62K 
30: R18         Shareholders' Equity                                HTML     36K 
31: R19         Stock-Based Compensation                            HTML     89K 
32: R20         Employee Benefit Plans                              HTML    150K 
33: R21         Indemnifications                                    HTML     33K 
34: R22         Income Taxes                                        HTML    117K 
35: R23         Commitments and Contingencies                       HTML     39K 
36: R24         Major Customers and Concentrations of Credit Risk   HTML     54K 
37: R25         Business Segment Information                        HTML     84K 
38: R26         Consolidated Valuation and Qualifying Accounts      HTML     58K 
39: R27         Summary of Significant Accounting Policies          HTML    128K 
                (Policies)                                                       
40: R28         Summary of Significant Accounting Policies          HTML    111K 
                (Tables)                                                         
41: R29         Business Combinations (Tables)                      HTML     49K 
42: R30         Inventories (Tables)                                HTML     39K 
43: R31         Property and Equipment, Net (Tables)                HTML     45K 
44: R32         Leases (Tables)                                     HTML     84K 
45: R33         Goodwill and Other Intangible Assets (Tables)       HTML    111K 
46: R34         Accrued and Other Liabilities (Tables)              HTML     38K 
47: R35         Long-Term Debt (Tables)                             HTML     56K 
48: R36         Stock-Based Compensation (Tables)                   HTML     97K 
49: R37         Employee Benefit Plans (Tables)                     HTML    157K 
50: R38         Income Taxes (Tables)                               HTML    115K 
51: R39         Major Customers and Concentrations of Credit Risk   HTML     54K 
                (Tables)                                                         
52: R40         Business Segment Information (Tables)               HTML     82K 
53: R41         Summary of Significant Accounting Policies -        HTML     97K 
                Narrative (Details)                                              
54: R42         Summary of Significant Accounting Policies -        HTML     39K 
                Supplemental Cash Flow Information (Details)                     
55: R43         Summary of Significant Accounting Policies -        HTML     35K 
                Contact Assets and Liabilities (Details)                         
56: R44         Summary of Significant Accounting Policies -        HTML     39K 
                Remaining Performance Obligation (Details)                       
57: R45         Summary of Significant Accounting Policies -        HTML     64K 
                Disaggregated Revenue (Details)                                  
58: R46         Summary of Significant Accounting Policies -        HTML     66K 
                Weighted Average Number of Shares Outstanding Used               
                to Compute Earnings Per Share (Details)                          
59: R47         Summary of Significant Accounting Policies -        HTML     34K 
                Weighted Average Number of Shares Outstanding                    
                Excluded from Computation of Diluted Earnings                    
                (Details)                                                        
60: R48         Business Combinations - Narrative (Details)         HTML     49K 
61: R49         Business Combinations - Fair Value of Assets and    HTML     63K 
                Liabilities Acquired (Details)                                   
62: R50         Business Combinations - Estimated Fair Value of     HTML     49K 
                Intangible Assets Acquired (Details)                             
63: R51         Inventories - (Details)                             HTML     38K 
64: R52         Property and Equipment, Net - (Details)             HTML     63K 
65: R53         Leases - Narrative (Details)                        HTML     61K 
66: R54         Leases - Lease Costs (Details)                      HTML     40K 
67: R55         Leases - Supplemental Cash Flow (Details)           HTML     43K 
68: R56         Leases - Weighted Average Remaining Lease Term and  HTML     41K 
                Discount Rate (Details)                                          
69: R57         Leases - Undiscounted Cash Flows (Details)          HTML     70K 
70: R58         Goodwill and Other Intangible Assets - Carrying     HTML     49K 
                Amount of Goodwill (Details)                                     
71: R59         Goodwill and Other Intangible Assets - Narrative    HTML     55K 
                (Details)                                                        
72: R60         Goodwill and Other Intangible Assets - Carrying     HTML     74K 
                Amount of Finite-lived and Other Intangible Assets               
                (Details)                                                        
73: R61         Goodwill and Other Intangible Assets - Future       HTML     54K 
                Amortization Expense of Other Intangible Assets                  
                (Details)                                                        
74: R62         Accrued and Other Liabilities (Details)             HTML     38K 
75: R63         Long-Term Debt - Summary (Details)                  HTML     50K 
76: R64         Long-Term Debt - Future Long-Term Debt Payment      HTML     49K 
                (Details)                                                        
77: R65         Long-Term Debt - Narrative (Details)                HTML    184K 
78: R66         Shareholders' Equity (Details)                      HTML     36K 
79: R67         Stock-Based Compensation - Narrative (Details)      HTML    122K 
80: R68         Stock-Based Compensation - Option Activity          HTML     74K 
                (Details)                                                        
81: R69         Stock-Based Compensation - Changes in Nonvested     HTML     49K 
                Stock Options (Details)                                          
82: R70         Stock-Based Compensation - Assumptions Used for     HTML     41K 
                Estimating Fair Value of Share Based Payment Award               
                (Details)                                                        
83: R71         Stock-Based Compensation - Restricted Stock         HTML     62K 
                Activity (Details)                                               
84: R72         Employee Benefit Plans - Narrative (Details)        HTML     65K 
85: R73         Employee Benefit Plans - Components of Net          HTML     45K 
                Periodic Pension Cost for Defined Benefit Pension                
                Plan and Retirement Plan (Details)                               
86: R74         Employee Benefit Plans - Reclassifications from     HTML     39K 
                Accumulated Other Comprehensive Income (Details)                 
87: R75         Employee Benefit Plans - Obligation and Funded      HTML     88K 
                Status of Defined Benefit Pension Plan and                       
                Retirement Plan (Details)                                        
88: R76         Employee Benefit Plans - Pension Plan Asset         HTML     39K 
                Allocations (Details)                                            
89: R77         Employee Benefit Plans - Asset Allocation Ranges    HTML     42K 
                (Details)                                                        
90: R78         Employee Benefit Plans - Return on Current and      HTML     70K 
                Target Asset Allocation (Details)                                
91: R79         Employee Benefit Plans - Weighted-average           HTML     43K 
                Assumptions Used to Determine Benefit Obligations                
                (Details)                                                        
92: R80         Employee Benefit Plans - Future Benefit Payments    HTML     47K 
                Under Pension Plans (Details)                                    
93: R81         Income Taxes - Schedule of Components of Provision  HTML     53K 
                (Benefit) for Income Taxes (Details)                             
94: R82         Income Taxes - Narrative (Details)                  HTML     59K 
95: R83         Income Taxes - Schedule of Deferred Income Taxes    HTML     88K 
                (Details)                                                        
96: R84         Income Taxes - Variation Between Expected and       HTML     63K 
                Effective Tax Rate (Details)                                     
97: R85         Income Taxes - Schedule of Changes in Unrecognized  HTML     42K 
                Tax Benefit (Details)                                            
98: R86         Commitments and Contingencies (Details)             HTML     77K 
99: R87         Major Customers and Concentrations of Credit Risk   HTML     48K 
                - Sales to Major Customers (Details)                             
100: R88         Major Customers and Concentrations of Credit Risk   HTML     45K  
                - Receivables from Customers (Details)                           
101: R89         Major Customers and Concentrations of Credit Risk   HTML     41K  
                - Narrative (Details)                                            
102: R90         Business Segment Information - Narrative (Details)  HTML     40K  
103: R91         Business Segment Information - Financial            HTML     59K  
                Information by Reportable Segment (Details)                      
104: R92         Business Segment Information - Segment Assets       HTML     48K  
                (Details)                                                        
105: R93         Consolidated Valuation and Qualifying Accounts      HTML     47K  
                (Details)                                                        
106: R9999       Uncategorized Items - dco-20211231.htm              HTML     48K  
109: XML         IDEA XML File -- Filing Summary                      XML    205K  
107: XML         XBRL Instance -- dco-20211231_htm                    XML   3.32M  
108: EXCEL       IDEA Workbook of Financial Reports                  XLSX    148K  
 9: EX-101.CAL  XBRL Calculations -- dco-20211231_cal                XML    331K 
10: EX-101.DEF  XBRL Definitions -- dco-20211231_def                 XML    865K 
11: EX-101.LAB  XBRL Labels -- dco-20211231_lab                      XML   2.48M 
12: EX-101.PRE  XBRL Presentations -- dco-20211231_pre               XML   1.50M 
 8: EX-101.SCH  XBRL Schema -- dco-20211231                          XSD    225K 
110: JSON        XBRL Instance as JSON Data -- MetaLinks              603±   867K  
111: ZIP         XBRL Zipped Folder -- 0001628280-22-003518-xbrl      Zip    584K  


‘EX-101.LAB’   —   XBRL Labels — dco-20211231_lab


This Exhibit is an XBRL XML File.


                                                                                                                                                                                
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<link:label id="lab_us-gaap_SupplementalCashFlowInformationAbstract_label_en-US" xlink:label="lab_us-gaap_SupplementalCashFlowInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Supplemental Cash Flow Information [Abstract] </link:label>
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<link:label id="lab_srt_NameOfMajorCustomerDomain_label_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer [Domain] </link:label>
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<link:label id="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
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<link:label id="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_2b6596fd-82ac-4a27-a97b-44ced36cc8d8_terseLabel_en-US" xlink:label="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> State </link:label>
<link:label id="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current State and Local Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_5ab981d5-0e8c-4d36-a864-a7c3a0c19ec2_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vested (in shares) </link:label>
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<link:label id="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock_5706845f-9162-4d90-bc00-8dc253c15567_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition </link:label>
<link:label id="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Acquisition Related Costs </link:label>
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<link:label id="lab_dco_GoodwillAndIntangibleAssetsLineItems_ee40031f-4470-46f8-afc8-5fb76f7d9186_terseLabel_en-US" xlink:label="lab_dco_GoodwillAndIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Intangible Assets [Line Items] </link:label>
<link:label id="lab_dco_GoodwillAndIntangibleAssetsLineItems_label_en-US" xlink:label="lab_dco_GoodwillAndIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Intangible Assets [Line Items] </link:label>
<link:label id="lab_dco_GoodwillAndIntangibleAssetsLineItems_documentation_en-US" xlink:label="lab_dco_GoodwillAndIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Intangible Assets [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_GoodwillAndIntangibleAssetsLineItems" xlink:href="dco-20211231.xsd#dco_GoodwillAndIntangibleAssetsLineItems"/>
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<link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_226492b5-3684-4248-abb9-a489aa5994ce_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerAsset" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract assets </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerAsset_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Contract with Customer, Asset </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerAsset"/>
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<link:label id="lab_dei_SecurityExchangeName_e41f5aff-6005-4e2b-9e50-7fae3a1866e6_terseLabel_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Security Exchange Name </link:label>
<link:label id="lab_dei_SecurityExchangeName_label_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Security Exchange Name </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_SecurityExchangeName"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_SecurityExchangeName" xlink:to="lab_dei_SecurityExchangeName" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_b5eb93ed-97fd-4b66-a9ce-24c3a7ea297d_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Forfeited (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
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<link:label id="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_a718d50b-630a-4d6d-99bb-3ca63f60ce99_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Contract with Customer, Asset and Liability </link:label>
<link:label id="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedInCalculationsAbstract_b15141e7-ed7e-45e9-a7e4-f1882c5e211f_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedInCalculationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Discount rate used to determine value of obligations </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedInCalculationsAbstract_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedInCalculationsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Assumptions Used in Calculations [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedInCalculationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedInCalculationsAbstract"/>
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<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_68618609-9f9e-4a4d-a22e-635f8a6ef9ed_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating leases </link:label>
<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Weighted Average Remaining Lease Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
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<link:label id="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_41a22924-ef75-44ff-80bb-57efef73ac1e_terseLabel_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current liabilities </link:label>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_label_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liability, Defined Benefit Plan, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:to="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4b6ba393-ad33-4ad5-b545-4098cedf149e_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
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<link:label id="lab_us-gaap_DerivativesPolicyTextBlock_771d1933-33d8-4905-bca4-f95285e021b4_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativesPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instruments </link:label>
<link:label id="lab_us-gaap_DerivativesPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_DerivativesPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivatives, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativesPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativesPolicyTextBlock" xlink:to="lab_us-gaap_DerivativesPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_a5767964-1acf-4f05-b838-1e989e49f402_totalLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Increase in Cash and Cash Equivalents </link:label>
<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_label_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
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<link:label id="lab_us-gaap_InventoriesMember_944f20fc-ea77-44cb-b417-6d5fac14fcfc_terseLabel_en-US" xlink:label="lab_us-gaap_InventoriesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories </link:label>
<link:label id="lab_us-gaap_InventoriesMember_label_en-US" xlink:label="lab_us-gaap_InventoriesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoriesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoriesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoriesMember" xlink:to="lab_us-gaap_InventoriesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_d551852b-525b-4f9b-b867-d41382cc12a2_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected volatility </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
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<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_c603618c-615b-4005-9bbb-b39dda5e2141_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Two </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
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<link:label id="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_5dc06b40-8287-4167-8fa3-b73c5515f5cd_negatedLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangibles </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Intangible Assets </link:label>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_588c537a-9fb8-408c-b1b5-61878ee3d147_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate intrinsic value of stock options exercised </link:label>
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<link:label id="lab_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock_4f8810ab-4900-4e30-91db-27015e3a0315_terseLabel_en-US" xlink:label="lab_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Reclassification out of Accumulated Other Comprehensive Income </link:label>
<link:label id="lab_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_TaxCreditCarryforwardLineItems_a11da8e3-b256-462d-8c85-4ace5a836cd6_terseLabel_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax Credit Carryforward [Line Items] </link:label>
<link:label id="lab_us-gaap_TaxCreditCarryforwardLineItems_label_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax Credit Carryforward [Line Items] </link:label>
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<link:label id="lab_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_6647f029-e33e-44da-a1bf-0d97238ffa93_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Charged to (Reduction of) Costs and Expenses </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense </link:label>
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<link:label id="lab_us-gaap_LesseeLeaseDescriptionLineItems_70ff3b0c-3c66-4655-872b-ef1b889b675a_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeLeaseDescriptionLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Description [Line Items] </link:label>
<link:label id="lab_us-gaap_LesseeLeaseDescriptionLineItems_label_en-US" xlink:label="lab_us-gaap_LesseeLeaseDescriptionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Description [Line Items] </link:label>
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<link:label id="lab_us-gaap_AmortizationOfIntangibleAssets_30cc8bb4-504d-48cb-99c3-3b455f2e2fc8_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization expense of intangible asset </link:label>
<link:label id="lab_us-gaap_AmortizationOfIntangibleAssets_label_en-US" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of Intangible Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
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<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_bc3b5a30-a66f-4695-8e1c-c46c264b58d0_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangible assets </link:label>
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<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_f91950e5-a86a-48a3-9e7c-fa3ebc5aa68f_terseLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additions for tax positions related to prior years </link:label>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_label_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanDebtSecurityMember_43eb0bcd-76eb-4906-8604-095bcbe5440e_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanDebtSecurityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt securities </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanDebtSecurityMember_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanDebtSecurityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Debt Security [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDebtSecurityMember"/>
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<link:label id="lab_dco_DeferredTaxAssetsOperatingLeaseLiability_44b9f949-7c77-4c4f-bc2e-212d6235d420_terseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease liabilities </link:label>
<link:label id="lab_dco_DeferredTaxAssetsOperatingLeaseLiability_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Operating Lease Liability </link:label>
<link:label id="lab_dco_DeferredTaxAssetsOperatingLeaseLiability_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Operating Lease Liability </link:label>
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<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_9bc5e88f-f11d-45a2-9479-954e32e2a550_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating leases </link:label>
<link:label id="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Weighted Average Discount Rate, Percent </link:label>
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<link:label id="lab_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_882963e6-9864-4830-96f4-6b88472faf26_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Inventories </link:label>
<link:label id="lab_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Inventory, Current [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_77f9dc15-8e64-4dac-aecf-1da49793a6c3_terseLabel_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock options and stock units (in shares) </link:label>
<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount </link:label>
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<link:label id="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_6c104bb9-cbda-4eab-89f6-527bfb7c162b_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract liability revenue </link:label>
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<link:label id="lab_us-gaap_DeferredTaxAssetsNet_e52ea681-7023-4eff-8745-748093c5fcb1_totalLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total gross deferred tax assets, net of valuation allowance </link:label>
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<link:label id="lab_us-gaap_BusinessCombinationAndAssetAcquisitionAbstract_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationAndAssetAcquisitionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination and Asset Acquisition [Abstract] </link:label>
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<link:label id="lab_us-gaap_BusinessAcquisitionAxis_8e915efd-a1d1-4c9f-9b0e-669bd2378072_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition [Axis] </link:label>
<link:label id="lab_us-gaap_BusinessAcquisitionAxis_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition [Axis] </link:label>
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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="lab_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_316633b5-61db-4c7d-9196-c00777de79f0_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Award Type [Domain] </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a964a483-80d6-4805-8e06-ea4c669d922e_verboseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Award Type [Domain] </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Award Type [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
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<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_952d9d78-de32-4789-af5c-bf26958a7bf9_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract"/>
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<link:label id="lab_dei_LocalPhoneNumber_43108d2a-1a4e-48be-ab98-dbd0beddbd40_terseLabel_en-US" xlink:label="lab_dei_LocalPhoneNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Local Phone Number </link:label>
<link:label id="lab_dei_LocalPhoneNumber_label_en-US" xlink:label="lab_dei_LocalPhoneNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Local Phone Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_LocalPhoneNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_LocalPhoneNumber" xlink:to="lab_dei_LocalPhoneNumber" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_33a5475d-1b95-4fd0-84fb-16f317744217_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of actuarial losses </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Amortization of Gain (Loss) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_bce345e7-ea99-43f9-bb77-1abeaa8e6cf3_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Exercisable at end of period (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
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<link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock_fb4ebfe1-32c6-4dd2-8758-dd30da363959_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill </link:label>
<link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill and Intangible Assets, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock"/>
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<link:label id="lab_dco_SpiritAerosystemsMember_cdf17e95-7fbc-4212-96f5-91a723d60094_terseLabel_en-US" xlink:label="lab_dco_SpiritAerosystemsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Spirit </link:label>
<link:label id="lab_dco_SpiritAerosystemsMember_label_en-US" xlink:label="lab_dco_SpiritAerosystemsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Spirit Aerosystems [Member] </link:label>
<link:label id="lab_dco_SpiritAerosystemsMember_documentation_en-US" xlink:label="lab_dco_SpiritAerosystemsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Spirit Aerosystems [Member] </link:label>
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<link:label id="lab_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_91b52bf5-4865-4b3e-8d18-96edea68e972_terseLabel_en-US" xlink:label="lab_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decrease in unrecognized tax benefits is reasonably possible </link:label>
<link:label id="lab_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_label_en-US" xlink:label="lab_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Decrease in Unrecognized Tax Benefits is Reasonably Possible </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible"/>
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<link:label id="lab_dco_DeferredTaxAssetsEmployeeRelatedObligations_8a951cc3-50e5-4c3c-92d0-6f1155cd5fe9_terseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsEmployeeRelatedObligations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employment-related accruals </link:label>
<link:label id="lab_dco_DeferredTaxAssetsEmployeeRelatedObligations_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsEmployeeRelatedObligations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Employee Related Obligations </link:label>
<link:label id="lab_dco_DeferredTaxAssetsEmployeeRelatedObligations_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsEmployeeRelatedObligations" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Employee Related Obligations </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxAssetsEmployeeRelatedObligations" xlink:href="dco-20211231.xsd#dco_DeferredTaxAssetsEmployeeRelatedObligations"/>
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<link:label id="lab_us-gaap_RetainedEarningsMember_67531f42-181e-4262-a133-bf6fa7aa45c6_terseLabel_en-US" xlink:label="lab_us-gaap_RetainedEarningsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retained Earnings </link:label>
<link:label id="lab_us-gaap_RetainedEarningsMember_label_en-US" xlink:label="lab_us-gaap_RetainedEarningsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retained Earnings [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetainedEarningsMember" xlink:to="lab_us-gaap_RetainedEarningsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_e5bfe71e-998c-4e9b-be0d-197ff0a2ae50_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Discount rate used to determine pension expense </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract"/>
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<link:label id="lab_us-gaap_AreaOfRealEstateProperty_da483c71-8e26-4649-b594-f83b9fb0d721_terseLabel_en-US" xlink:label="lab_us-gaap_AreaOfRealEstateProperty" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Real estate property (in sqft) </link:label>
<link:label id="lab_us-gaap_AreaOfRealEstateProperty_label_en-US" xlink:label="lab_us-gaap_AreaOfRealEstateProperty" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Area of Real Estate Property </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AreaOfRealEstateProperty" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AreaOfRealEstateProperty"/>
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<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_a78cf987-4142-4ad5-a628-7797d3bdc7d5_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Stock Options </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfSharesRollForward"/>
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<link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_762a8c10-a70f-4ef7-93c6-b0919facf6c1_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
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<link:label id="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_ff0ff1f5-7b91-4ca2-8ec0-ce5f93d6d1e4_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts receivable </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Accounts Receivable </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid_c0657f15-6037-4a8d-980a-6afb964f9b03_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Purchases of property and equipment not paid </link:label>
<link:label id="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid_label_en-US" xlink:label="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital Expenditures Incurred but Not yet Paid </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="lab_us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_da6db537-c243-4f5b-8abd-11409c422cc4_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Line Items] </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_c70d85f2-b357-4781-bd3a-68bc52d732d7_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other non-current liabilities </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityWellKnownSeasonedIssuer_44797dfe-fbc2-4edf-bc38-44edfb7efcf7_terseLabel_en-US" xlink:label="lab_dei_EntityWellKnownSeasonedIssuer" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Well-known Seasoned Issuer </link:label>
<link:label id="lab_dei_EntityWellKnownSeasonedIssuer_label_en-US" xlink:label="lab_dei_EntityWellKnownSeasonedIssuer" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Well-known Seasoned Issuer </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityWellKnownSeasonedIssuer"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityWellKnownSeasonedIssuer" xlink:to="lab_dei_EntityWellKnownSeasonedIssuer" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementBenefitExpense_e0e01328-4d3a-47e3-a423-06bc2caf872b_totalLabel_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementBenefitExpense" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net periodic pension cost </link:label>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementBenefitExpense_label_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementBenefitExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension and Other Postretirement Benefits Cost (Reversal of Cost) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PensionAndOtherPostretirementBenefitExpense" xlink:to="lab_us-gaap_PensionAndOtherPostretirementBenefitExpense" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ProceedsReceivedFromGrants_09093550-57ec-4b70-aead-dd46e744782c_terseLabel_en-US" xlink:label="lab_dco_ProceedsReceivedFromGrants" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds received from grants </link:label>
<link:label id="lab_dco_ProceedsReceivedFromGrants_label_en-US" xlink:label="lab_dco_ProceedsReceivedFromGrants" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds Received From Grants </link:label>
<link:label id="lab_dco_ProceedsReceivedFromGrants_documentation_en-US" xlink:label="lab_dco_ProceedsReceivedFromGrants" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds Received From Grants </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ProceedsReceivedFromGrants" xlink:href="dco-20211231.xsd#dco_ProceedsReceivedFromGrants"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ProceedsReceivedFromGrants" xlink:to="lab_dco_ProceedsReceivedFromGrants" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeasePrincipalPayments_2cb94993-7147-4055-a6be-f824bae03f6d_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeasePrincipalPayments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Financing cash flows from finance leases </link:label>
<link:label id="lab_us-gaap_FinanceLeasePrincipalPayments_label_en-US" xlink:label="lab_us-gaap_FinanceLeasePrincipalPayments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Principal Payments </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeasePrincipalPayments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeasePrincipalPayments" xlink:to="lab_us-gaap_FinanceLeasePrincipalPayments" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50_3417ae9f-1396-4613-a8e2-e69e35b32864_terseLabel_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of excess cash flow payment when leverage ratio is less than or equal to 2.50 </link:label>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50_label_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Percentage of Excess Cash Flow Payment When Leverage Ratio is Less Than or Equal to 2.50 </link:label>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50_documentation_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Percentage of Excess Cash Flow Payment When Leverage Ratio is Less Than or Equal to 2.50 </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50" xlink:href="dco-20211231.xsd#dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50" xlink:to="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessThanorEqualto2.50" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EarningsPerShareBasic_276489e7-fd62-4bf5-a293-c93f302bedfd_verboseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic earnings per share (in dollars per share) </link:label>
<link:label id="lab_us-gaap_EarningsPerShareBasic_ec52686e-b4e5-4982-a47e-5dcc96738447_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic (in dollars per share) </link:label>
<link:label id="lab_us-gaap_EarningsPerShareBasic_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Basic </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasic"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareBasic" xlink:to="lab_us-gaap_EarningsPerShareBasic" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_8bba01fe-4b48-4afa-a0a0-942f894d7358_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning of period (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_7cc278ee-6401-4b01-9add-9d958ecc65e5_periodEndLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending of period (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_f2b2f68e-8dfd-4a34-98d5-d6e01b6c34b3_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2022 </link:label>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year One </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="arc" order="1"/>
<link:label id="lab_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_8a20b713-ac88-449d-a705-a85c663bd21c_terseLabel_en-US" xlink:label="lab_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidated Valuation and Qualifying Accounts </link:label>
<link:label id="lab_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_label_en-US" xlink:label="lab_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:to="lab_srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_61fd700f-6c6a-4809-8343-3872ad7a372e_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension liability </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liability, Defined Benefit Pension Plan, Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent" xlink:to="lab_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
<link:label id="lab_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_090e463e-b34b-4e51-bde2-470b584a4324_terseLabel_en-US" xlink:label="lab_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumulative Effect, Period of Adoption, Adjustment </link:label>
<link:label id="lab_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_label_en-US" xlink:label="lab_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumulative Effect, Period of Adoption, Adjustment [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:to="lab_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_MachineryAndEquipmentMember_f033fc48-5157-41f1-89d4-69afa15d6282_terseLabel_en-US" xlink:label="lab_us-gaap_MachineryAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Machinery and equipment </link:label>
<link:label id="lab_us-gaap_MachineryAndEquipmentMember_label_en-US" xlink:label="lab_us-gaap_MachineryAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Machinery and Equipment [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MachineryAndEquipmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MachineryAndEquipmentMember" xlink:to="lab_us-gaap_MachineryAndEquipmentMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxLiabilities_06951021-0ca0-4a2b-a69e-5ef69e0fcbf2_negatedTotalLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net deferred tax liabilities </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilities_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilities" xlink:to="lab_us-gaap_DeferredTaxLiabilities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherNoncashIncomeExpense_5cab6962-ac2b-4e1f-a379-1ae169c83b24_negatedLabel_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other </link:label>
<link:label id="lab_us-gaap_OtherNoncashIncomeExpense_label_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Noncash Income (Expense) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNoncashIncomeExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherNoncashIncomeExpense" xlink:to="lab_us-gaap_OtherNoncashIncomeExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_dd7a0399-9630-48d3-b020-422330236701_negatedLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Property, Plant and Equipment </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_df8b12b4-9458-4a4d-99fc-a0a81d2f1883_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] </link:label>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LossContingencyReceivableProceeds_f69c4e0b-1b0e-4c5d-9783-4e42d7ace019_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingencyReceivableProceeds" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss contingency, receivable, proceeds </link:label>
<link:label id="lab_us-gaap_LossContingencyReceivableProceeds_label_en-US" xlink:label="lab_us-gaap_LossContingencyReceivableProceeds" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency, Receivable, Proceeds </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyReceivableProceeds" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyReceivableProceeds"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyReceivableProceeds" xlink:to="lab_us-gaap_LossContingencyReceivableProceeds" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityVoluntaryFilers_606f0e31-f66f-4349-90d9-d61628f6858d_terseLabel_en-US" xlink:label="lab_dei_EntityVoluntaryFilers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Voluntary Filers </link:label>
<link:label id="lab_dei_EntityVoluntaryFilers_label_en-US" xlink:label="lab_dei_EntityVoluntaryFilers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Voluntary Filers </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityVoluntaryFilers" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityVoluntaryFilers"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityVoluntaryFilers" xlink:to="lab_dei_EntityVoluntaryFilers" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PlanAssetCategoriesDomain_a4dec2ff-8ccd-4631-a135-9e42935480c1_terseLabel_en-US" xlink:label="lab_us-gaap_PlanAssetCategoriesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Category [Domain] </link:label>
<link:label id="lab_us-gaap_PlanAssetCategoriesDomain_label_en-US" xlink:label="lab_us-gaap_PlanAssetCategoriesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Category [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain" xlink:to="lab_us-gaap_PlanAssetCategoriesDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromIssuanceOfSecuredDebt_02b97110-c0fd-4ee8-816d-2d8d556e400c_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings from term loans </link:label>
<link:label id="lab_us-gaap_ProceedsFromIssuanceOfSecuredDebt_label_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Issuance of Secured Debt </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:to="lab_us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_3ee62573-4806-4a78-b837-3868dd137679_verboseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current portion of long-term debt </link:label>
<link:label id="lab_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_label_en-US" xlink:label="lab_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt and Lease Obligation, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:to="lab_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_d0d3583e-0eaa-4739-96a8-75203613c166_verboseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total fair value of options expensed before tax benefits </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PlanNameAxis_584567a6-8b1f-4d23-bd4c-96632893d56c_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Plan Name [Axis] </link:label>
<link:label id="lab_us-gaap_PlanNameAxis_label_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Plan Name [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="lab_us-gaap_PlanNameAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebt_a9625963-7fc2-4fb9-9e21-3fe108038bfe_totalLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total long-term debt, net of debt issuance costs </link:label>
<link:label id="lab_us-gaap_LongTermDebt_label_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebt" xlink:to="lab_us-gaap_LongTermDebt" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueInputsLevel1Member_d210e704-39a6-4bd6-9f97-9efd1e43fac8_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Level 1 </link:label>
<link:label id="lab_us-gaap_FairValueInputsLevel1Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel1Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value, Inputs, Level 1 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel1Member" xlink:to="lab_us-gaap_FairValueInputsLevel1Member" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_90479247-eac7-4748-a462-77539454c9f5_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash Flows from Investing Activities </link:label>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeTaxDisclosureAbstract_2d326e42-26fc-46d5-a293-e44bcc9f80a3_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Disclosure [Abstract] </link:label>
<link:label id="lab_us-gaap_IncomeTaxDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract" xlink:to="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntitySmallBusiness_5e9e9b0a-8850-460e-b491-7ef98ca5ddb0_terseLabel_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Small Business </link:label>
<link:label id="lab_dei_EntitySmallBusiness_label_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Small Business </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntitySmallBusiness"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntitySmallBusiness" xlink:to="lab_dei_EntitySmallBusiness" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_a7adfa82-1015-4435-8d9f-a9b76081259b_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Leases </link:label>
<link:label id="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, Payment, Due [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="lab_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BaseRateMember_6daa3f95-1309-4c61-a70c-01324d6ddaf4_terseLabel_en-US" xlink:label="lab_us-gaap_BaseRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Base Rate </link:label>
<link:label id="lab_us-gaap_BaseRateMember_label_en-US" xlink:label="lab_us-gaap_BaseRateMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Base Rate [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BaseRateMember"/>
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<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_label_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions </link:label>
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<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems_14a25180-ff64-47ef-9078-1e5b7abc456c_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets [Line Items] </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets [Line Items] </link:label>
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<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation_1b4ca0b3-45cc-4f31-9fab-5b4ede371cda_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred compensation </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation </link:label>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount_f3999bf3-f60a-4832-b11d-4ee4701b39c4_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Excess tax benefit over compensation cost recognized, amount </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount"/>
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<link:label id="lab_dco_PercentageOfNetSales_93d531f2-5975-4650-9265-d81177b2e131_terseLabel_en-US" xlink:label="lab_dco_PercentageOfNetSales" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of sales </link:label>
<link:label id="lab_dco_PercentageOfNetSales_label_en-US" xlink:label="lab_dco_PercentageOfNetSales" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Net Sales </link:label>
<link:label id="lab_dco_PercentageOfNetSales_documentation_en-US" xlink:label="lab_dco_PercentageOfNetSales" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of Net Sales </link:label>
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<link:label id="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract_2aaeef49-61ff-4794-baf0-00add0b0cc51_terseLabel_en-US" xlink:label="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted- Average Exercise Price Per Share </link:label>
<link:label id="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract_label_en-US" xlink:label="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Exercise Price [Abstract] </link:label>
<link:label id="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract_documentation_en-US" xlink:label="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract" xlink:href="dco-20211231.xsd#dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract"/>
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<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ca326699-d7d9-46cc-ab58-ffa01d659cfc_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities and Shareholders’ Equity </link:label>
<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities and Equity [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_e8c37166-16b8-4fd9-937e-eab7c44a9ce1_terseLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized tax benefits that would impact effective tax rate </link:label>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_label_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized Tax Benefits that Would Impact Effective Tax Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
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<link:label id="lab_us-gaap_IncreaseDecreaseInAccountsPayable_fd506489-54e1-4ae6-bf35-880a689c913d_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts payable </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInAccountsPayable_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsPayable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Accounts Payable </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
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<link:label id="lab_us-gaap_InterestRateSwapMember_a18df284-93c5-4277-a09f-44940ad63dcc_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateSwapMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Swap </link:label>
<link:label id="lab_us-gaap_InterestRateSwapMember_label_en-US" xlink:label="lab_us-gaap_InterestRateSwapMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Swap [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateSwapMember" xlink:to="lab_us-gaap_InterestRateSwapMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DeferredTaxAssetsTaxCreditCarryforwardsState_9f037f02-c1c0-48d2-abe4-2e56c1e5942c_verboseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsTaxCreditCarryforwardsState" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> State tax credit carryforwards </link:label>
<link:label id="lab_dco_DeferredTaxAssetsTaxCreditCarryforwardsState_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsTaxCreditCarryforwardsState" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Tax Credit Carryforwards State </link:label>
<link:label id="lab_dco_DeferredTaxAssetsTaxCreditCarryforwardsState_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsTaxCreditCarryforwardsState" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Tax Credit Carryforwards, State </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxAssetsTaxCreditCarryforwardsState" xlink:href="dco-20211231.xsd#dco_DeferredTaxAssetsTaxCreditCarryforwardsState"/>
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<link:label id="lab_us-gaap_HedgingAssetsNoncurrent_a805a8a9-82bd-432f-b529-5a2cb3b9e95e_terseLabel_en-US" xlink:label="lab_us-gaap_HedgingAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest rate hedge </link:label>
<link:label id="lab_us-gaap_HedgingAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_HedgingAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Assets, Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingAssetsNoncurrent"/>
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<link:label id="lab_srt_ValuationAndQualifyingAccountsDisclosureTable_a2c8d550-07ec-434f-96eb-4f74ba8a4566_terseLabel_en-US" xlink:label="lab_srt_ValuationAndQualifyingAccountsDisclosureTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] </link:label>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPayments_d3895fa7-5a4e-4b3d-adf7-5bd067b5183d_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPayments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected dividends </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPayments_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPayments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Payments </link:label>
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<link:label id="lab_dei_EntityInteractiveDataCurrent_d7e12344-adb7-43de-9413-898769d688d4_terseLabel_en-US" xlink:label="lab_dei_EntityInteractiveDataCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Interactive Data Current </link:label>
<link:label id="lab_dei_EntityInteractiveDataCurrent_label_en-US" xlink:label="lab_dei_EntityInteractiveDataCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Interactive Data Current </link:label>
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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityInteractiveDataCurrent" xlink:to="lab_dei_EntityInteractiveDataCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_058e4e6b-cfaa-4c08-93d9-0fec716c9b27_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, after Year Five </link:label>
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<link:label id="lab_us-gaap_PaymentsToAcquireBusinessThreeNetOfCashAcquired_83cd40aa-c27e-4b39-bf5d-51ee1a70e620_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessThreeNetOfCashAcquired" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for acquisition of Nobles Worldwide, Inc., net of cash acquired </link:label>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessThreeNetOfCashAcquired_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessThreeNetOfCashAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to Acquire Business Three, Net of Cash Acquired </link:label>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_abcc1b73-e278-463a-a9a2-5bc121c247e8_negatedLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Research and development tax credits </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Tax Credit, Research, Percent </link:label>
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<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_26eab843-f079-4f6c-9b81-b4605957ecb6_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock options exercised </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued During Period, Value, Stock Options Exercised </link:label>
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<link:label id="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock_9c09266c-fcd6-47b8-8178-76cb6ab2c61e_terseLabel_en-US" xlink:label="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Assets </link:label>
<link:label id="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock_label_en-US" xlink:label="lab_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reconciliation of Assets from Segment to Consolidated [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock"/>
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<link:label id="lab_us-gaap_RetirementPlanNameAxis_59224cb9-6fc5-4971-8b8b-70113d9f504b_terseLabel_en-US" xlink:label="lab_us-gaap_RetirementPlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Name [Axis] </link:label>
<link:label id="lab_us-gaap_RetirementPlanNameAxis_label_en-US" xlink:label="lab_us-gaap_RetirementPlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Name [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanNameAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanNameAxis"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanCashMember_89de9063-ae8e-41b8-abd9-ebbe77a17040_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanCashMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanCashMember_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanCashMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Cash [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCashMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanCashMember"/>
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<link:label id="lab_dco_DefinedBenefitPlanUnrecognizedActuarialNetGainsLosses_dbaf3e42-f2e9-47ac-9fa5-e30cd90704ef_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanUnrecognizedActuarialNetGainsLosses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liability (gain) loss </link:label>
<link:label id="lab_dco_DefinedBenefitPlanUnrecognizedActuarialNetGainsLosses_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanUnrecognizedActuarialNetGainsLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Unrecognized Actuarial Net Gains Losses </link:label>
<link:label id="lab_dco_DefinedBenefitPlanUnrecognizedActuarialNetGainsLosses_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanUnrecognizedActuarialNetGainsLosses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Unrecognized Actuarial Net Gains Losses </link:label>
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<link:label id="lab_us-gaap_BalanceSheetLocationDomain_53ba0f37-f886-4df1-9d10-641d1b5d8dad_terseLabel_en-US" xlink:label="lab_us-gaap_BalanceSheetLocationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance Sheet Location [Domain] </link:label>
<link:label id="lab_us-gaap_BalanceSheetLocationDomain_label_en-US" xlink:label="lab_us-gaap_BalanceSheetLocationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance Sheet Location [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
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<link:label id="lab_us-gaap_UnrecognizedTaxBenefits_4dcc8535-7648-463f-844c-5eef23e324a0_terseLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefits" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized tax benefits </link:label>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefits_94dc8efd-b1d5-43a7-a66f-b4cbd0e4d951_periodStartLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefits" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning Balance </link:label>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefits_1516071a-b388-457b-ba0b-64c5f8ef78c7_periodEndLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefits" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending Balance </link:label>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefits_label_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized Tax Benefits </link:label>
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<link:label id="lab_us-gaap_DeferredTaxAssetsGross_2335e444-9633-4074-92e8-8a267e1d020f_totalLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsGross" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total gross deferred tax assets </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsGross_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Gross </link:label>
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<link:label id="lab_us-gaap_IncomeTaxAuthorityDomain_025a275a-fa0a-4b77-bb19-b5348094e848_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Authority [Domain] </link:label>
<link:label id="lab_us-gaap_IncomeTaxAuthorityDomain_label_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Authority [Domain] </link:label>
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<link:label id="lab_dei_EntityCommonStockSharesOutstanding_174ba708-07be-4f26-9be7-c203a8fb6fec_terseLabel_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </link:label>
<link:label id="lab_dei_EntityCommonStockSharesOutstanding_label_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </link:label>
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<link:label id="lab_dei_EntityAddressStateOrProvince_b6e53c06-c39d-4603-85c4-69418b21cf02_terseLabel_en-US" xlink:label="lab_dei_EntityAddressStateOrProvince" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, State or Province </link:label>
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<link:label id="lab_us-gaap_LesseeFinanceLeasesTextBlock_bda98d40-657b-440c-9319-cb51458e84bd_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeFinanceLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leases </link:label>
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<link:label id="lab_us-gaap_DeferredIncomeTaxAssetsNet_ac302ccb-cb3f-4df4-91c5-0dacec61e3cf_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxAssetsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Taxes </link:label>
<link:label id="lab_us-gaap_DeferredIncomeTaxAssetsNet_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxAssetsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Tax Assets, Net </link:label>
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<link:label id="lab_us-gaap_LiabilitiesCurrentAbstract_e1876752-cbc7-4b70-80f2-e99234e4975d_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Liabilities </link:label>
<link:label id="lab_us-gaap_LiabilitiesCurrentAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities, Current [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="lab_us-gaap_LiabilitiesCurrentAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_7e5e8802-9160-4af3-b657-5bce01967d0a_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease liabilities </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Operating Lease Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GeneralAndAdministrativeExpense_bd39c037-73a2-4c04-84ce-2fb8ae97661b_negatedLabel_en-US" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Corporate General and Administrative Expenses </link:label>
<link:label id="lab_us-gaap_GeneralAndAdministrativeExpense_label_en-US" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> General and Administrative Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:to="lab_us-gaap_GeneralAndAdministrativeExpense" xlink:type="arc" order="1"/>
<link:label id="lab_dco_CommercialAerospaceMember_af679f51-39b6-49f5-a05f-f80e82512333_terseLabel_en-US" xlink:label="lab_dco_CommercialAerospaceMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commercial aerospace </link:label>
<link:label id="lab_dco_CommercialAerospaceMember_label_en-US" xlink:label="lab_dco_CommercialAerospaceMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commercial Aerospace [Member] </link:label>
<link:label id="lab_dco_CommercialAerospaceMember_documentation_en-US" xlink:label="lab_dco_CommercialAerospaceMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commercial Aerospace [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_CommercialAerospaceMember" xlink:href="dco-20211231.xsd#dco_CommercialAerospaceMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_CommercialAerospaceMember" xlink:to="lab_dco_CommercialAerospaceMember" xlink:type="arc" order="1"/>
<link:label id="lab_srt_RestatementAxis_8dfd2293-8ef1-45dc-8f9d-cb1b2136a482_terseLabel_en-US" xlink:label="lab_srt_RestatementAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revision of Prior Period [Axis] </link:label>
<link:label id="lab_srt_RestatementAxis_label_en-US" xlink:label="lab_srt_RestatementAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revision of Prior Period [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RestatementAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RestatementAxis" xlink:to="lab_srt_RestatementAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharesOutstanding_3a245a6f-02e0-4cf9-a087-b0723f7cfcf0_periodStartLabel_en-US" xlink:label="lab_us-gaap_SharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance (in shares) </link:label>
<link:label id="lab_us-gaap_SharesOutstanding_c1e92119-c54a-4478-8ba4-5076400ecce9_periodEndLabel_en-US" xlink:label="lab_us-gaap_SharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending balance (in shares) </link:label>
<link:label id="lab_us-gaap_SharesOutstanding_label_en-US" xlink:label="lab_us-gaap_SharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Shares, Outstanding </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharesOutstanding" xlink:to="lab_us-gaap_SharesOutstanding" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_eb07a3da-54ad-436a-ae35-fb735c57364e_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Exercisable at end of period (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InventoryDisclosureTextBlock_303e8531-aa4c-4836-9d9c-84e6bcc1dc0a_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories </link:label>
<link:label id="lab_us-gaap_InventoryDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_InventoryDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryDisclosureTextBlock" xlink:to="lab_us-gaap_InventoryDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccountingPoliciesAbstract_bbdcf2f5-d875-4d09-bcfd-414997df48eb_terseLabel_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounting Policies [Abstract] </link:label>
<link:label id="lab_us-gaap_AccountingPoliciesAbstract_label_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounting Policies [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountingPoliciesAbstract" xlink:to="lab_us-gaap_AccountingPoliciesAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_fa585c8b-3639-4d14-9452-844b6c29826a_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment, Year Four </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:to="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract_80d67276-017f-4a29-829b-b7c0e97be07f_terseLabel_en-US" xlink:label="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disclosure of Guarantees and Indemnifications [Abstract] </link:label>
<link:label id="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract_label_en-US" xlink:label="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disclosure of Guarantees and Indemnifications [Abstract] </link:label>
<link:label id="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract_documentation_en-US" xlink:label="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disclosure of Guarantees and Indemnifications [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DisclosureofGuaranteesandIndemnificationsAbstract" xlink:href="dco-20211231.xsd#dco_DisclosureofGuaranteesandIndemnificationsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DisclosureofGuaranteesandIndemnificationsAbstract" xlink:to="lab_dco_DisclosureofGuaranteesandIndemnificationsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_5d641ac7-0256-4b28-a4c4-5ff7849ad762_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average remaining contractual term </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_b539a1fe-82b3-47b0-910a-80ec911714b6_verboseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Outstanding </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_081fbfcf-d1aa-42c8-8b11-320651233d5d_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instrument [Axis] </link:label>
<link:label id="lab_us-gaap_DerivativeInstrumentRiskAxis_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Instrument [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis" xlink:to="lab_us-gaap_DerivativeInstrumentRiskAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CurrentFederalTaxExpenseBenefit_eb38bc5b-8fd0-4056-8926-edc87bbee914_terseLabel_en-US" xlink:label="lab_us-gaap_CurrentFederalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Federal </link:label>
<link:label id="lab_us-gaap_CurrentFederalTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_CurrentFederalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Federal Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentFederalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="lab_us-gaap_CurrentFederalTaxExpenseBenefit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLeaseLiability_4dedc731-236e-4072-9884-a381e2eb9dfc_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total </link:label>
<link:label id="lab_us-gaap_OperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiability" xlink:to="lab_us-gaap_OperatingLeaseLiability" xlink:type="arc" order="1"/>
<link:label id="lab_dei_DocumentTransitionReport_eded7a4e-9ace-4ce0-b6e9-27f4a5ea929f_terseLabel_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Transition Report </link:label>
<link:label id="lab_dei_DocumentTransitionReport_label_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Transition Report </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentTransitionReport"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentTransitionReport" xlink:to="lab_dei_DocumentTransitionReport" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_ce08599b-d507-47d6-98c3-97e29069ea5c_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated net actuarial loss for the defined benefit pension plan </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear"/>
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<link:label id="lab_us-gaap_CommonStockValue_7498c500-37da-49dc-b908-58d9fff7b874_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock - $0.01 par value; 35,000,000 shares authorized; 11,925,087 and 11,728,212 shares issued and outstanding at December 31, 2021 and 2020, respectively </link:label>
<link:label id="lab_us-gaap_CommonStockValue_label_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Value, Issued </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue"/>
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<link:label id="lab_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_0109fb65-58e1-4b2d-8e21-a20ca1d22b53_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance leases </link:label>
<link:label id="lab_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Weighted Average Discount Rate, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent"/>
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<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6b06a04e-fbef-4021-8eed-c13dacb8a12c_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average period </link:label>
<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_label_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
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<link:label id="lab_us-gaap_CustomerConcentrationRiskMember_c13c80d0-691d-43c5-9373-4c2ca38f7205_terseLabel_en-US" xlink:label="lab_us-gaap_CustomerConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer Concentration Risk </link:label>
<link:label id="lab_us-gaap_CustomerConcentrationRiskMember_label_en-US" xlink:label="lab_us-gaap_CustomerConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer Concentration Risk [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerConcentrationRiskMember"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_f6d803cf-5210-44b8-9906-cf794ac658b0_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Outstanding at beginning of period (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_bbab6705-d5d1-48bb-a63d-c9cd2da391fd_periodEndLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Outstanding at ending of period (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
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<link:label id="lab_us-gaap_LesseeOperatingLeasesTextBlock_38f843a2-f950-4da1-a166-96ff0344f100_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leases </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeasesTextBlock_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Leases [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeasesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeasesTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeasesTextBlock" xlink:to="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization_bb82dd54-d54a-465c-918f-8709623f914d_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of right-of-use assets </link:label>
<link:label id="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Right-of-Use Asset, Amortization </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_0a3587a4-ac1b-4b6d-9009-a7eec0003946_totalLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Funded status (underfunded) </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Funded (Unfunded) Status of Plan </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
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<link:label id="lab_us-gaap_BusinessCombinationDisclosureTextBlock_b6b4c10e-1aa8-4545-b5b5-988ca93f8402_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combinations </link:label>
<link:label id="lab_us-gaap_BusinessCombinationDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationDisclosureTextBlock"/>
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<link:label id="lab_dei_IcfrAuditorAttestationFlag_1c2df7cb-7088-4eb2-b5ac-dfd97c218141_terseLabel_en-US" xlink:label="lab_dei_IcfrAuditorAttestationFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> ICFR Auditor Attestation Flag </link:label>
<link:label id="lab_dei_IcfrAuditorAttestationFlag_label_en-US" xlink:label="lab_dei_IcfrAuditorAttestationFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> ICFR Auditor Attestation Flag </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_IcfrAuditorAttestationFlag" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_IcfrAuditorAttestationFlag"/>
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<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax_63e0e52d-0182-4fe8-b571-6b8a16c2aec9_verboseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrealized gain (loss) on cash flow hedge, tax expense (benefit) </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax"/>
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<link:label id="lab_us-gaap_GoodwillLineItems_ad74c2ae-909c-4335-b857-77445ec6d425_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill [Line Items] </link:label>
<link:label id="lab_us-gaap_GoodwillLineItems_label_en-US" xlink:label="lab_us-gaap_GoodwillLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillLineItems" xlink:to="lab_us-gaap_GoodwillLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_073bbacf-74b8-4542-95af-4878105fbe84_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of actuarial losses and prior service costs, net of tax of $309, $236, and $209 for 2021, 2020, and 2019, respectively </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_fe871b85-7e27-4c1c-99f4-3f1db8824c7a_totalLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net of tax </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax"/>
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<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessthanorEqualto3.25_f114cada-c1eb-4181-a8a3-2620c0883032_terseLabel_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessthanorEqualto3.25" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of excess cash flow payment when leverage ratio is less than or equal to 3.25 </link:label>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessthanorEqualto3.25_label_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisLessthanorEqualto3.25" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Percentage of Excess Cash Flow Payment When Leverage Ratio is Less than or Equal to 3.25 </link:label>
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<link:label id="lab_us-gaap_InterestIncomeExpenseNet_8f25c7f5-7b0e-4300-a911-a10850eaaab0_terseLabel_en-US" xlink:label="lab_us-gaap_InterestIncomeExpenseNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Expense </link:label>
<link:label id="lab_us-gaap_InterestIncomeExpenseNet_label_en-US" xlink:label="lab_us-gaap_InterestIncomeExpenseNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Income (Expense), Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
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<link:label id="lab_dco_PensionObligationsAndOtherLongTermLiabilities_2fc41205-18a5-4bad-b02c-a52e70a6832b_terseLabel_en-US" xlink:label="lab_dco_PensionObligationsAndOtherLongTermLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest on labarge deferred compensation plan </link:label>
<link:label id="lab_dco_PensionObligationsAndOtherLongTermLiabilities_label_en-US" xlink:label="lab_dco_PensionObligationsAndOtherLongTermLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension Obligations And Other Long Term Liabilities </link:label>
<link:label id="lab_dco_PensionObligationsAndOtherLongTermLiabilities_documentation_en-US" xlink:label="lab_dco_PensionObligationsAndOtherLongTermLiabilities" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension Obligations And Other Long Term Liabilities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_PensionObligationsAndOtherLongTermLiabilities" xlink:href="dco-20211231.xsd#dco_PensionObligationsAndOtherLongTermLiabilities"/>
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<link:label id="lab_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock_c1b47275-b8e1-468f-9103-0b84eb62becf_terseLabel_en-US" xlink:label="lab_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reconciliation of Unrecognized Tax Benefits </link:label>
<link:label id="lab_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock_label_en-US" xlink:label="lab_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Income Tax Contingencies [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfIncomeTaxContingenciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SummaryOfIncomeTaxContingenciesTextBlock"/>
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<link:label id="lab_us-gaap_IncomeTaxAuthorityAxis_33b8d0e8-e7f5-4590-b993-3198da02a7d8_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Authority [Axis] </link:label>
<link:label id="lab_us-gaap_IncomeTaxAuthorityAxis_label_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Authority [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
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<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_a192fac2-0b19-4442-9eb4-9d0629be27bb_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, to be Paid, after Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive"/>
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<link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember_68fc6b44-7b54-41eb-9cc3-b9e63f2c483f_terseLabel_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling, General and Administrative Expenses </link:label>
<link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember_label_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling, General and Administrative Expenses [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:to="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccruedLiabilitiesCurrent_7908efd8-28c2-4561-b779-e7bc5eafdb43_terseLabel_en-US" xlink:label="lab_us-gaap_AccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued and other liabilities </link:label>
<link:label id="lab_us-gaap_AccruedLiabilitiesCurrent_1efd2d8d-c49b-4e5a-996a-c67a05d4c8d7_totalLabel_en-US" xlink:label="lab_us-gaap_AccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total </link:label>
<link:label id="lab_us-gaap_AccruedLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_AccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Liabilities, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:to="lab_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a0d38c1c-b33a-401c-9208-b1c2ee8220c8_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Revenues </link:label>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_ba69922d-b7c5-406a-be2e-f76e62e8e85d_verboseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenues </link:label>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue from Contract with Customer, Excluding Assessed Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
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<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_3b3a01d9-765a-41c9-98f7-fff8af64fc2b_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock-based compensation </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost"/>
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<link:label id="lab_dco_New2018TermLoanMaturingNovember212025Member_38ab9ba9-aa2f-4670-abb6-803bc760b01a_terseLabel_en-US" xlink:label="lab_dco_New2018TermLoanMaturingNovember212025Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2018 Term Loan </link:label>
<link:label id="lab_dco_New2018TermLoanMaturingNovember212025Member_label_en-US" xlink:label="lab_dco_New2018TermLoanMaturingNovember212025Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New 2018 Term Loan Maturing November 21, 2025 [Member] </link:label>
<link:label id="lab_dco_New2018TermLoanMaturingNovember212025Member_documentation_en-US" xlink:label="lab_dco_New2018TermLoanMaturingNovember212025Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New 2018 Term Loan Maturing November 21, 2025 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_New2018TermLoanMaturingNovember212025Member" xlink:href="dco-20211231.xsd#dco_New2018TermLoanMaturingNovember212025Member"/>
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<link:label id="lab_us-gaap_EmployeeStockOptionMember_2219e5e2-69de-4164-9315-cad21316e0f9_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeStockOptionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Options </link:label>
<link:label id="lab_us-gaap_EmployeeStockOptionMember_label_en-US" xlink:label="lab_us-gaap_EmployeeStockOptionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Option [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeStockOptionMember" xlink:to="lab_us-gaap_EmployeeStockOptionMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_b2de49cd-c630-4bb9-ad0c-90277178b899_negatedLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Actuarial gains (losses) arising during the period, net of tax benefit of $902, $701, and $502 for 2021, 2020, and 2019, respectively </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax"/>
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<link:label id="lab_srt_ConsolidationItemsDomain_c1f40fe0-a883-4394-b107-7fd6523e62b2_terseLabel_en-US" xlink:label="lab_srt_ConsolidationItemsDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidation Items [Domain] </link:label>
<link:label id="lab_srt_ConsolidationItemsDomain_label_en-US" xlink:label="lab_srt_ConsolidationItemsDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidation Items [Domain] </link:label>
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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidationItemsDomain" xlink:to="lab_srt_ConsolidationItemsDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_4992df4d-e778-44fc-8460-17b542fa364b_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Hierarchy and NAV [Axis] </link:label>
<link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Hierarchy and NAV [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
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<link:label id="lab_us-gaap_EquityAbstract_d01bca83-4851-4bd2-ba21-b66ad8789e7b_terseLabel_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity [Abstract] </link:label>
<link:label id="lab_us-gaap_EquityAbstract_label_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity [Abstract] </link:label>
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<link:label id="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_e97fad50-1db0-41b1-8837-a6a8728b8d8d_terseLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Other Comprehensive Loss </link:label>
<link:label id="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ComprehensiveIncomePolicyPolicyTextBlock"/>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_d00ab06d-d3a5-4747-89e6-9854c886e410_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax credit, percent </link:label>
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<link:label id="lab_us-gaap_VariableRateAxis_c123665c-5e4c-4443-8bf1-8e2318ffb350_terseLabel_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Axis] </link:label>
<link:label id="lab_us-gaap_VariableRateAxis_label_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Axis] </link:label>
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<link:label id="lab_us-gaap_SegmentReportingDisclosureTextBlock_5f2abfa1-36d7-4162-a266-5567e55e5319_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Segment Information </link:label>
<link:label id="lab_us-gaap_SegmentReportingDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_SegmentReportingDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting Disclosure [Text Block] </link:label>
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<link:label id="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_25904edc-e6ee-48f8-833f-15befc48108e_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance leases </link:label>
<link:label id="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Weighted Average Remaining Lease Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1"/>
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<link:label id="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_69e8b4ec-a4ed-4cf9-ad37-6009a67249f3_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Property, Plant and Equipment [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
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<link:label id="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_61f5647a-0683-4d8f-855e-d38f3df22c7c_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Stockholders' Equity [Roll Forward] </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Stockholders' Equity [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
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<link:label id="lab_dei_DocumentFiscalYearFocus_b611af60-8d77-4b69-b205-56beafe2773a_terseLabel_en-US" xlink:label="lab_dei_DocumentFiscalYearFocus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Year Focus </link:label>
<link:label id="lab_dei_DocumentFiscalYearFocus_label_en-US" xlink:label="lab_dei_DocumentFiscalYearFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Year Focus </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentFiscalYearFocus"/>
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<link:label id="lab_dco_DefinedContributionPlanEmployerMatchingPercentOfEmployeeContribution_e66e68b3-3ce6-4dc9-ad25-5d7aec8f60dc_terseLabel_en-US" xlink:label="lab_dco_DefinedContributionPlanEmployerMatchingPercentOfEmployeeContribution" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contribution by employer towards defined benefit plan </link:label>
<link:label id="lab_dco_DefinedContributionPlanEmployerMatchingPercentOfEmployeeContribution_label_en-US" xlink:label="lab_dco_DefinedContributionPlanEmployerMatchingPercentOfEmployeeContribution" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan Employer Matching Percent Of Employee Contribution </link:label>
<link:label id="lab_dco_DefinedContributionPlanEmployerMatchingPercentOfEmployeeContribution_documentation_en-US" xlink:label="lab_dco_DefinedContributionPlanEmployerMatchingPercentOfEmployeeContribution" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan Employer Matching Percent Of Employee Contribution </link:label>
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<link:label id="lab_us-gaap_PropertyPlantAndEquipmentAbstract_05bbb584-6e73-4583-bc3f-4f25f18305bc_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Abstract] </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentAbstract_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Abstract] </link:label>
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<link:label id="lab_us-gaap_VariableRateDomain_df5fa90f-8b11-4cc7-a0eb-f64a536dcf24_terseLabel_en-US" xlink:label="lab_us-gaap_VariableRateDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Domain] </link:label>
<link:label id="lab_us-gaap_VariableRateDomain_label_en-US" xlink:label="lab_us-gaap_VariableRateDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Variable Rate [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VariableRateDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableRateDomain" xlink:to="lab_us-gaap_VariableRateDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AdditionalPaidInCapitalMember_56f030d4-42aa-4906-8fc0-16d656f5b586_terseLabel_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapitalMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional Paid-In Capital </link:label>
<link:label id="lab_us-gaap_AdditionalPaidInCapitalMember_label_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapitalMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional Paid-in Capital [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:to="lab_us-gaap_AdditionalPaidInCapitalMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RepaymentsOfDebt_89ef75cf-e95c-4832-b486-bac022878190_negatedLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfDebt" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of other debt </link:label>
<link:label id="lab_us-gaap_RepaymentsOfDebt_1378ac06-d1aa-471f-8682-5b0c49ba9ad7_terseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of debt </link:label>
<link:label id="lab_us-gaap_RepaymentsOfDebt_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Debt </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfDebt"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_6f188384-0b10-497b-a258-38e87e92e45a_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2027 - 2031 </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years </link:label>
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<link:label id="lab_dco_TaxBenefitForExerciseOfStockOptionsAndIssuanceOfSharesUponVestingOfRestrictedStockGrants_6bcb2ec8-d69d-4173-9e87-9d8804733da4_terseLabel_en-US" xlink:label="lab_dco_TaxBenefitForExerciseOfStockOptionsAndIssuanceOfSharesUponVestingOfRestrictedStockGrants" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax benefits realized for the tax deductions from options exercised </link:label>
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<link:label id="lab_us-gaap_LongtermDebtTypeDomain_b53bf8b7-de24-4846-9f8a-f902971c0e96_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Type [Domain] </link:label>
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<link:label id="lab_us-gaap_ProceedsFromLinesOfCredit_bc0928f8-8221-4acd-9edd-5dd39f7de28b_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from lines of credit </link:label>
<link:label id="lab_us-gaap_ProceedsFromLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Lines of Credit </link:label>
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<link:label id="lab_us-gaap_OtherAssetsMember_27920830-e958-4af7-a391-821074659974_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Assets </link:label>
<link:label id="lab_us-gaap_OtherAssetsMember_label_en-US" xlink:label="lab_us-gaap_OtherAssetsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Assets [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsMember"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_15564d58-b0a0-4f7e-b663-9563ab57d26a_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] </link:label>
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<link:label id="lab_srt_MaximumMember_label_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum [Member] </link:label>
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<link:label id="lab_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Accrued Liabilities [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_AwardTypeAxis_a2823e68-51dc-467b-8f56-7a7cdf13fb7c_terseLabel_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Award Type [Axis] </link:label>
<link:label id="lab_us-gaap_AwardTypeAxis_label_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Award Type [Axis] </link:label>
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<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_2811209a-b985-406b-8384-1c1b7f412242_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash Flows from Financing Activities </link:label>
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<link:label id="lab_dco_LesseeLeaseTerminationPeriod_f9af16b4-fe10-4e15-bf5f-c6594e3cb993_terseLabel_en-US" xlink:label="lab_dco_LesseeLeaseTerminationPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease termination period </link:label>
<link:label id="lab_dco_LesseeLeaseTerminationPeriod_label_en-US" xlink:label="lab_dco_LesseeLeaseTerminationPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Termination Period </link:label>
<link:label id="lab_dco_LesseeLeaseTerminationPeriod_documentation_en-US" xlink:label="lab_dco_LesseeLeaseTerminationPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Termination Period </link:label>
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<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_a7dc5f6c-b580-408c-8e86-4b258f6abab8_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Lessee, Operating Lease, Liability, Maturity </link:label>
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<link:label id="lab_us-gaap_StockholdersEquity_8715c63c-cb8b-48a6-89e2-99ccdc495439_totalLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Shareholders’ Equity </link:label>
<link:label id="lab_us-gaap_StockholdersEquity_a7aa64ac-691b-4b8a-bf30-4e5adc4b3151_periodStartLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance </link:label>
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<link:label id="lab_us-gaap_StockholdersEquity_label_en-US" xlink:label="lab_us-gaap_StockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Attributable to Parent </link:label>
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<link:label id="lab_dei_CityAreaCode_76caaf60-8a84-436f-80e9-80edc0726a7e_terseLabel_en-US" xlink:label="lab_dei_CityAreaCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> City Area Code </link:label>
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<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_a6f9a9e1-db54-4db9-9298-ec7e4e2f35d3_verboseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Exercisable </link:label>
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<link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_26e0c483-e087-440a-a0fb-b4abad597f4a_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill and Intangible Assets Disclosure [Abstract] </link:label>
<link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill and Intangible Assets Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount_14328f72-f707-49d7-bf9b-3172c835e17a_terseLabel_en-US" xlink:label="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance lease, lease not yet commenced, amount </link:label>
<link:label id="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount_label_en-US" xlink:label="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Finance Lease, Lease Not Yet Commenced, Amount </link:label>
<link:label id="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount_documentation_en-US" xlink:label="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Finance Lease, Lease Not Yet Commenced, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount" xlink:href="dco-20211231.xsd#dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount" xlink:to="lab_dco_LesseeFinanceLeaseLeaseNotYetCommencedAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_dab64dc1-ccd9-4822-8c0e-4cbb509eb31d_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Useful life </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Useful Life </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockholdersEquityAbstract_ded53d1b-1184-46ae-b13d-6698ebb86769_terseLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Shareholders’ Equity </link:label>
<link:label id="lab_us-gaap_StockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_StockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Attributable to Parent [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityAbstract" xlink:to="lab_us-gaap_StockholdersEquityAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact_e36a96ee-dd14-4b98-bc52-8c885e61a17d_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax impact </link:label>
<link:label id="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Accumulated Other Comprehensive Income Loss Tax Impact </link:label>
<link:label id="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Accumulated Other Comprehensive Income Loss Tax Impact </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact" xlink:to="lab_dco_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossTaxImpact" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLeaseLiabilityNoncurrent_72f16771-dbb7-4b27-a85e-ea1094689086_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-Current Operating Lease Liabilities </link:label>
<link:label id="lab_us-gaap_OperatingLeaseLiabilityNoncurrent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Liability, Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue_d5df784c-2ee9-460e-85ca-624ee86d227c_totalLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total lease payments </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, Payment, Due </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CurrentIncomeTaxExpenseBenefit_652b51ca-6ce8-4d4c-ae11-71922f99ca97_totalLabel_en-US" xlink:label="lab_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current tax expense </link:label>
<link:label id="lab_us-gaap_CurrentIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Income Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentFaceAmount_13642abb-30a2-467b-b053-90976f8c412f_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt amount </link:label>
<link:label id="lab_us-gaap_DebtInstrumentFaceAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Face Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentFaceAmount" xlink:to="lab_us-gaap_DebtInstrumentFaceAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_517b7a7e-0759-453a-9709-6f19ac84c22e_totalLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized loss included in accumulated other comprehensive loss, net of tax </link:label>
<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax" xlink:type="arc" order="1"/>
<link:label id="lab_dco_MiscellaneousExpenses_c458cc1b-612c-42c2-bbaa-bf6df023a085_terseLabel_en-US" xlink:label="lab_dco_MiscellaneousExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Miscellaneous expenses </link:label>
<link:label id="lab_dco_MiscellaneousExpenses_label_en-US" xlink:label="lab_dco_MiscellaneousExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Miscellaneous Expenses </link:label>
<link:label id="lab_dco_MiscellaneousExpenses_documentation_en-US" xlink:label="lab_dco_MiscellaneousExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Miscellaneous Expenses </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_MiscellaneousExpenses" xlink:href="dco-20211231.xsd#dco_MiscellaneousExpenses"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_MiscellaneousExpenses" xlink:to="lab_dco_MiscellaneousExpenses" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_99286c5b-5894-4be4-9ebf-813f3adeab0d_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax benefit realized on vesting of options </link:label>
<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_label_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Expense, Tax Benefit </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:to="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingSegmentsMember_a47459d7-6ec6-45cc-a01e-982037a61fa6_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Segments </link:label>
<link:label id="lab_us-gaap_OperatingSegmentsMember_label_en-US" xlink:label="lab_us-gaap_OperatingSegmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Segments [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingSegmentsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingSegmentsMember" xlink:to="lab_us-gaap_OperatingSegmentsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9e92e887-0405-4532-b9b8-a3cb2861b029_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Defined Benefit Plans Disclosures [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Defined Benefit Plans Disclosures [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:to="lab_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RestrictedStockUnitsRSUMember_b9fcad0d-078c-4028-99fa-fe80c0309f24_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted Stock Units </link:label>
<link:label id="lab_us-gaap_RestrictedStockUnitsRSUMember_label_en-US" xlink:label="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restricted Stock Units (RSUs) [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:to="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_3120966b-45c1-48c2-bed1-3454a6f54cff_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Provision for loss on contracts </link:label>
<link:label id="lab_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract with Customer, Asset, Allowance for Credit Loss </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss" xlink:to="lab_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss" xlink:type="arc" order="1"/>
<link:label id="lab_srt_RestatementDomain_0078684b-a352-4836-bb2e-a0df085d57a5_terseLabel_en-US" xlink:label="lab_srt_RestatementDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revision of Prior Period [Domain] </link:label>
<link:label id="lab_srt_RestatementDomain_label_en-US" xlink:label="lab_srt_RestatementDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revision of Prior Period [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RestatementDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RestatementDomain" xlink:to="lab_srt_RestatementDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiability_6cda9d02-dfac-4bdc-ba42-9ddda4f20a55_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiability_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiability" xlink:to="lab_us-gaap_FinanceLeaseLiability" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredIncomeTaxLiabilities_fc7255de-b133-49bc-9637-cb829d5cc31b_negatedTotalLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total gross deferred tax liabilities </link:label>
<link:label id="lab_us-gaap_DeferredIncomeTaxLiabilities_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredIncomeTaxLiabilities" xlink:to="lab_us-gaap_DeferredIncomeTaxLiabilities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessAcquisitionLineItems_121df3a3-5731-4bcf-b5b4-2d9c2d0974d0_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition [Line Items] </link:label>
<link:label id="lab_us-gaap_BusinessAcquisitionLineItems_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems" xlink:to="lab_us-gaap_BusinessAcquisitionLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_591b909e-cf65-44c7-a294-cce66431a667_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity securities </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_df83f94e-2126-4cb3-ab7f-91f3641c3393_verboseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equities </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_739d105e-67eb-4135-8284-421e667665cd_netLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equities </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Equity Securities [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:to="lab_us-gaap_DefinedBenefitPlanEquitySecuritiesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_21f1aafe-d71a-4b9a-b3c0-0235a8083936_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Second Anniversary </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Tranche Two [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:to="lab_us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DeferredTaxAssetsPension_d3e106c7-94c8-4294-bcbf-258b02b35c73_terseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsPension" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension obligation </link:label>
<link:label id="lab_dco_DeferredTaxAssetsPension_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsPension" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Pension </link:label>
<link:label id="lab_dco_DeferredTaxAssetsPension_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsPension" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Pension </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxAssetsPension" xlink:href="dco-20211231.xsd#dco_DeferredTaxAssetsPension"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DeferredTaxAssetsPension" xlink:to="lab_dco_DeferredTaxAssetsPension" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans_07378916-461d-472b-8052-371907a89444_terseLabel_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of incentive plans </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans_label_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Number of Incentive Plans </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans_documentation_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Number of Incentive Plans </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans" xlink:href="dco-20211231.xsd#dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans" xlink:to="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofIncentivePlans" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeStatementAbstract_939cf9d3-4e02-4dbe-ba8e-f0aaa2072bc3_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement [Abstract] </link:label>
<link:label id="lab_us-gaap_IncomeStatementAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="lab_us-gaap_IncomeStatementAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityRegistrantName_e53ecfa4-6e83-4def-9ba3-65734c665126_terseLabel_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Registrant Name </link:label>
<link:label id="lab_dei_EntityRegistrantName_label_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Registrant Name </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityRegistrantName"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityRegistrantName" xlink:to="lab_dei_EntityRegistrantName" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_e5a34c12-c26d-4a57-b97f-470fb02343b1_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Class [Domain] </link:label>
<link:label id="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_label_en-US" xlink:label="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Class [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="lab_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:type="arc" order="1"/>
<link:label id="lab_dco_IndefiniteLivedAssetsAbstract_98bc069b-23e3-408d-86ec-f51559d66b75_terseLabel_en-US" xlink:label="lab_dco_IndefiniteLivedAssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived assets </link:label>
<link:label id="lab_dco_IndefiniteLivedAssetsAbstract_label_en-US" xlink:label="lab_dco_IndefiniteLivedAssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite lived Assets [Abstract] </link:label>
<link:label id="lab_dco_IndefiniteLivedAssetsAbstract_documentation_en-US" xlink:label="lab_dco_IndefiniteLivedAssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite lived Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_IndefiniteLivedAssetsAbstract" xlink:href="dco-20211231.xsd#dco_IndefiniteLivedAssetsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_IndefiniteLivedAssetsAbstract" xlink:to="lab_dco_IndefiniteLivedAssetsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_e5498066-8e56-4550-b562-b6814f0ff021_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts receivable </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_9c3c18bc-bc87-4647-90b3-0fee0431f207_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, to be Paid, Year Three </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_1de5d8ad-5783-4a50-8e09-ce22ce6c56e7_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, to be Paid, Year Four </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesDeductions_d3eab3c4-3c72-450a-b8a8-5eb46b08e55a_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deductions </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesDeductions_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:to="lab_us-gaap_ValuationAllowancesAndReservesDeductions" xlink:type="arc" order="1"/>
<link:label id="lab_dco_FinanceLeaseCost_9d56ebd2-4b33-4f95-b224-7e31c6708ca0_totalLabel_en-US" xlink:label="lab_dco_FinanceLeaseCost" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total finance lease expense </link:label>
<link:label id="lab_dco_FinanceLeaseCost_label_en-US" xlink:label="lab_dco_FinanceLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Cost </link:label>
<link:label id="lab_dco_FinanceLeaseCost_documentation_en-US" xlink:label="lab_dco_FinanceLeaseCost" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Cost </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_FinanceLeaseCost" xlink:href="dco-20211231.xsd#dco_FinanceLeaseCost"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_FinanceLeaseCost" xlink:to="lab_dco_FinanceLeaseCost" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_4055fbd5-6c4f-4d92-96d0-8e89e80fc1a2_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Forfeited (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeTaxExpenseBenefit_0d505190-d0c4-46c2-8328-5d3624e1a234_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Expense </link:label>
<link:label id="lab_us-gaap_IncomeTaxExpenseBenefit_d71b7132-76cb-479d-aa7b-4bff10154d4a_totalLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income tax expense </link:label>
<link:label id="lab_us-gaap_IncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_IncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_60d136c2-3e49-4c2f-8892-a79d1def83e2_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment, Year Three </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:to="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccountsReceivableNetCurrent_2f0c0de1-68a2-4228-b206-12f031632a65_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsReceivableNetCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts receivable (net of allowance for credit losses of $1,098 and $1,552 at December 31, 2021 and 2020, respectively) </link:label>
<link:label id="lab_us-gaap_AccountsReceivableNetCurrent_label_en-US" xlink:label="lab_us-gaap_AccountsReceivableNetCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable, after Allowance for Credit Loss, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableNetCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsReceivableNetCurrent" xlink:to="lab_us-gaap_AccountsReceivableNetCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsInventory_9cceb18a-1a69-4c37-b2bb-9b4bb1d1ddca_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsInventory" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory reserves </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsInventory_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsInventory" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Inventory </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsInventory" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsInventory"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsInventory" xlink:to="lab_us-gaap_DeferredTaxAssetsInventory" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_1ab18ac7-38cc-4d1c-838c-7d86e65cbc7f_periodStartLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance (in shares) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_e66e5ed2-a0cb-4037-ba78-f6ff2cc5171d_periodEndLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending balance (in shares) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityTaxIdentificationNumber_c6848047-ac3d-47c6-aae3-b0aef3682b64_terseLabel_en-US" xlink:label="lab_dei_EntityTaxIdentificationNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Tax Identification Number </link:label>
<link:label id="lab_dei_EntityTaxIdentificationNumber_label_en-US" xlink:label="lab_dei_EntityTaxIdentificationNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Tax Identification Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityTaxIdentificationNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityTaxIdentificationNumber" xlink:to="lab_dei_EntityTaxIdentificationNumber" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_3ff8b8bb-ea70-4844-a7bb-beb11aa4dab4_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Change in plan assets </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:to="lab_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward" xlink:type="arc" order="1"/>
<link:label id="lab_dei_DocumentFiscalPeriodFocus_9981427c-ef64-4a24-89aa-a87f69c8c8b7_terseLabel_en-US" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Period Focus </link:label>
<link:label id="lab_dei_DocumentFiscalPeriodFocus_label_en-US" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Fiscal Period Focus </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentFiscalPeriodFocus"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFiscalPeriodFocus" xlink:to="lab_dei_DocumentFiscalPeriodFocus" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AssetsCurrent_6997f01e-f3b2-426a-a8e6-adbc71559d6c_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Current Assets </link:label>
<link:label id="lab_us-gaap_AssetsCurrent_label_en-US" xlink:label="lab_us-gaap_AssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsCurrent" xlink:to="lab_us-gaap_AssetsCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccountsReceivableMember_9c8d7d93-0f19-4070-a2f4-135ef4b425ea_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsReceivableMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable </link:label>
<link:label id="lab_us-gaap_AccountsReceivableMember_label_en-US" xlink:label="lab_us-gaap_AccountsReceivableMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsReceivableMember" xlink:to="lab_us-gaap_AccountsReceivableMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_cc204c60-a405-4bdd-8b0f-1972abd10bc8_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems" xlink:to="lab_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_d0a3a4e8-f45c-4e0b-b182-67707084b383_totalLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total lease payments </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_c8de717c-6099-463a-98da-d78393515225_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Forfeited (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LeaseRemainingLeaseTerm_4da1d591-51c7-4f1e-a67d-75fa1a33dda2_terseLabel_en-US" xlink:label="lab_dco_LeaseRemainingLeaseTerm" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining lease term </link:label>
<link:label id="lab_dco_LeaseRemainingLeaseTerm_label_en-US" xlink:label="lab_dco_LeaseRemainingLeaseTerm" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Remaining Lease Term </link:label>
<link:label id="lab_dco_LeaseRemainingLeaseTerm_documentation_en-US" xlink:label="lab_dco_LeaseRemainingLeaseTerm" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Remaining Lease Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LeaseRemainingLeaseTerm" xlink:href="dco-20211231.xsd#dco_LeaseRemainingLeaseTerm"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LeaseRemainingLeaseTerm" xlink:to="lab_dco_LeaseRemainingLeaseTerm" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_6ff974c9-fd33-4df5-b195-dd1106ab26a8_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounting for Stock-Based Compensation </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockRepurchasedDuringPeriodValue_43dc6463-3a1d-459f-94b8-dfdcb9c62a32_negatedLabel_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodValue" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock repurchased related to the exercise of stock options and stock awards vested </link:label>
<link:label id="lab_us-gaap_StockRepurchasedDuringPeriodValue_label_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Repurchased During Period, Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockRepurchasedDuringPeriodValue" xlink:to="lab_us-gaap_StockRepurchasedDuringPeriodValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_6f52b236-08d2-4a40-85b8-9d7fe31ce96b_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Financial Position [Abstract] </link:label>
<link:label id="lab_us-gaap_StatementOfFinancialPositionAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Financial Position [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract" xlink:to="lab_us-gaap_StatementOfFinancialPositionAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_srt_ValuationAndQualifyingAccountsAbstract_048728e9-d503-4f1b-b2b5-133a05b765da_terseLabel_en-US" xlink:label="lab_srt_ValuationAndQualifyingAccountsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] </link:label>
<link:label id="lab_srt_ValuationAndQualifyingAccountsAbstract_label_en-US" xlink:label="lab_srt_ValuationAndQualifyingAccountsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsAbstract" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ValuationAndQualifyingAccountsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ValuationAndQualifyingAccountsAbstract" xlink:to="lab_srt_ValuationAndQualifyingAccountsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount_e1195077-87d4-40b5-ae9b-ec19597cf549_terseLabel_en-US" xlink:label="lab_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Prepayment amount of principal outstanding </link:label>
<link:label id="lab_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount_label_en-US" xlink:label="lab_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Prepayment Amount, Percentage of Principal Amount </link:label>
<link:label id="lab_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount_documentation_en-US" xlink:label="lab_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Prepayment Amount, Percentage of Principal Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount" xlink:href="dco-20211231.xsd#dco_DebtInstrumentPrepaymentAmountPercentageofPrincipalAmount"/>
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<link:label id="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_142b9b00-09e9-4ffc-9773-e0ed27068783_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value </link:label>
<link:label id="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Measurement, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
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<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_8958d8e0-9923-4dfa-9bac-6594dce3bacd_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized compensation cost related to stock option </link:label>
<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_label_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:to="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtCurrent_f4393cb7-81de-43fb-ba42-9f0def0a8b4d_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less current portion </link:label>
<link:label id="lab_us-gaap_LongTermDebtCurrent_label_en-US" xlink:label="lab_us-gaap_LongTermDebtCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Current Maturities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtCurrent" xlink:to="lab_us-gaap_LongTermDebtCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_37e8604e-984e-4f32-9de7-6a2b796d4a02_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Type [Domain] </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Lived Tangible Asset [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_644d7903-5f3a-42e2-aab5-5e3d56962bb3_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vested, (in dollars per share) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_d1538d6c-5856-49a0-8df7-b35c0f17e4e1_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Weighted Average Number of Shares Outstanding Used to Compute Earnings Per Share </link:label>
<link:label id="lab_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Weighted Average Number of Shares [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_d669799d-2507-49a0-8fd4-7b73ce9e7b11_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock-based compensation expense </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost"/>
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<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_eb1468e4-c8b5-4030-9c69-e0239a1d365a_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Compensation not yet recognized </link:label>
<link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_label_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_8a949f5e-33c8-4b16-9fd2-1df72df696ee_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grants (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_becce17f-b646-4f64-95ad-8534328b8449_verboseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Granted, (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
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<link:label id="lab_us-gaap_EquityComponentDomain_f935dc38-1b34-4195-a354-07b3a5a99666_terseLabel_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Component [Domain] </link:label>
<link:label id="lab_us-gaap_EquityComponentDomain_label_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Component [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="lab_us-gaap_EquityComponentDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet_9fecc8c6-c5a5-4b45-a623-990e0efe5186_terseLabel_en-US" xlink:label="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain on Sale-Leaseback </link:label>
<link:label id="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet_5b64e250-e868-4978-8600-25061c87aa75_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain on sale-leaseback </link:label>
<link:label id="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet_label_en-US" xlink:label="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale and Leaseback Transaction, Gain (Loss), Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleAndLeasebackTransactionGainLossNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:to="lab_us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses_a0ef4d20-59e3-413b-8920-d5879c135d28_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Prepaid insurance </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Prepaid Expenses </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPrepaidExpenses"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_8ab95c0b-3fc1-4cb4-9c6b-65f5b1d67a98_periodStartLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance, (in dollars per share) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_1ca0633f-0055-4583-878e-7680fea00ad3_periodEndLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending balance, (in dollars per share) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Option, Nonvested, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_ac749d54-b348-45b9-84a3-16b1e6bd3a9d_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2021 </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year One </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_c57bccd0-932d-4740-a056-fade414550ef_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Category [Axis] </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Category [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:to="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredFinanceCostsGross_2e4c74ca-fe19-4a51-889f-dc11c3f843d7_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fees paid to lenders to be capitalized </link:label>
<link:label id="lab_us-gaap_DeferredFinanceCostsGross_label_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Issuance Costs, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredFinanceCostsGross" xlink:to="lab_us-gaap_DeferredFinanceCostsGross" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherIncome_6f6f87b8-1e04-4d90-baa0-efcdf560d081_terseLabel_en-US" xlink:label="lab_us-gaap_OtherIncome" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Income, Net </link:label>
<link:label id="lab_us-gaap_OtherIncome_label_en-US" xlink:label="lab_us-gaap_OtherIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Income </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherIncome"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherIncome" xlink:to="lab_us-gaap_OtherIncome" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligation_30d1f7c4-618c-4787-8b19-6c00bde88ac9_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining performance obligation, amount </link:label>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligation_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligation" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligation" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_59e3ea5c-1b61-4a36-9bcc-a34f32b347d1_terseLabel_en-US" xlink:label="lab_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of fair value in excess of carrying amount </link:label>
<link:label id="lab_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_label_en-US" xlink:label="lab_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:to="lab_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock_6f0ee09c-453c-4acf-8928-034884b83f39_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Company's Pension Plan Asset Allocation, by Asset Category </link:label>
<link:label id="lab_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Allocation of Plan Assets [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_bb3f057a-8cc1-4f49-aae4-4f2633a15508_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Changes in valuation allowance </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IntangibleAssetsGrossExcludingGoodwill_c66c2719-91fb-4004-80d0-a3d1be7073c3_totalLabel_en-US" xlink:label="lab_us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangible assets, gross </link:label>
<link:label id="lab_us-gaap_IntangibleAssetsGrossExcludingGoodwill_label_en-US" xlink:label="lab_us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangible Assets, Gross (Excluding Goodwill) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:to="lab_us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_6365c637-8d0d-4b20-8522-8e9ceb12515d_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Four </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_603972fe-176e-4f9a-987a-f025272dbbb8_totalLabel_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Before Taxes </link:label>
<link:label id="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_label_en-US" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueInputsLevel2Member_e1aa111b-bdbd-4d8f-be22-290f718cef12_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Level 2 </link:label>
<link:label id="lab_us-gaap_FairValueInputsLevel2Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value, Inputs, Level 2 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel2Member" xlink:to="lab_us-gaap_FairValueInputsLevel2Member" xlink:type="arc" order="1"/>
<link:label id="lab_dei_AuditorLocation_d56b639b-4ee5-45d5-84c0-f875200c516e_terseLabel_en-US" xlink:label="lab_dei_AuditorLocation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Location </link:label>
<link:label id="lab_dei_AuditorLocation_label_en-US" xlink:label="lab_dei_AuditorLocation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Location </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_AuditorLocation" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorLocation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AuditorLocation" xlink:to="lab_dei_AuditorLocation" xlink:type="arc" order="1"/>
<link:label id="lab_dco_AccruedCompensationCurrent_fc9d5683-4512-4a6b-8857-07eb06904dbe_terseLabel_en-US" xlink:label="lab_dco_AccruedCompensationCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued compensation </link:label>
<link:label id="lab_dco_AccruedCompensationCurrent_label_en-US" xlink:label="lab_dco_AccruedCompensationCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Compensation Current </link:label>
<link:label id="lab_dco_AccruedCompensationCurrent_documentation_en-US" xlink:label="lab_dco_AccruedCompensationCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Compensation, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_AccruedCompensationCurrent" xlink:href="dco-20211231.xsd#dco_AccruedCompensationCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_AccruedCompensationCurrent" xlink:to="lab_dco_AccruedCompensationCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SegmentReportingAbstract_fc2bbc05-8111-4708-9824-15ddf8c44601_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting [Abstract] </link:label>
<link:label id="lab_us-gaap_SegmentReportingAbstract_label_en-US" xlink:label="lab_us-gaap_SegmentReportingAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingAbstract" xlink:to="lab_us-gaap_SegmentReportingAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_TypeOfRestructuringDomain_bbc441e7-69d8-48a6-8049-649bd2d766b1_terseLabel_en-US" xlink:label="lab_us-gaap_TypeOfRestructuringDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Type of Restructuring [Domain] </link:label>
<link:label id="lab_us-gaap_TypeOfRestructuringDomain_label_en-US" xlink:label="lab_us-gaap_TypeOfRestructuringDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Type of Restructuring [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TypeOfRestructuringDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TypeOfRestructuringDomain" xlink:to="lab_us-gaap_TypeOfRestructuringDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife_03d9e3da-91e4-4b53-80fd-14e00f9aeb8b_verboseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated useful life of intangible assets (in years) </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife_eb35a723-624b-4842-aaec-109de4315304_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Useful Life (In years) </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Useful Life </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseInterestExpense_ab167fc6-6518-4d9b-a8f5-a759198ba2b2_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest on lease liabilities </link:label>
<link:label id="lab_us-gaap_FinanceLeaseInterestExpense_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Interest Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseInterestExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseInterestExpense" xlink:to="lab_us-gaap_FinanceLeaseInterestExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_UseOfEstimates_c5aab9c6-3143-4b81-b3c4-ede206dd85ab_terseLabel_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Use of Estimates </link:label>
<link:label id="lab_us-gaap_UseOfEstimates_label_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Use of Estimates, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UseOfEstimates" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UseOfEstimates"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UseOfEstimates" xlink:to="lab_us-gaap_UseOfEstimates" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds_e7420aa4-a15f-4597-8be7-9882b7116b87_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total plan assets at fair value </link:label>
<link:label id="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Fair Value of Plan Assets Not Including Pooled Funds </link:label>
<link:label id="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Fair Value of Plan Assets Not Including Pooled Funds </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds" xlink:to="lab_dco_DefinedBenefitPlanFairValueofPlanAssetsNotIncludingPooledFunds" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_eab9fde4-45cd-416d-a67b-b7be4fe0bed6_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Leases </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, Payment, Due [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="lab_us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dei_Security12bTitle_4bdf9a68-b58c-4f99-b666-9fd9b87aa81a_terseLabel_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of 12(b) Security </link:label>
<link:label id="lab_dei_Security12bTitle_label_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of 12(b) Security </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_Security12bTitle"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_Security12bTitle" xlink:to="lab_dei_Security12bTitle" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredIncomeTaxesAndTaxCredits_67dd8d05-f101-45f4-b4e9-552d5edef143_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred income taxes </link:label>
<link:label id="lab_us-gaap_DeferredIncomeTaxesAndTaxCredits_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Taxes and Tax Credits </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxesAndTaxCredits"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:to="lab_us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount_6b6586e8-ec6f-4b14-a71d-4ac73b1c3376_terseLabel_en-US" xlink:label="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease, lease not yet commenced, amount </link:label>
<link:label id="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount_label_en-US" xlink:label="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Lease Not Yet Commenced, Amount </link:label>
<link:label id="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount_documentation_en-US" xlink:label="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Lease Not Yet Commenced, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount" xlink:href="dco-20211231.xsd#dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount" xlink:to="lab_dco_LesseeOperatingLeaseLeaseNotYetCommencedAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommonStockSharesAuthorized_42cbc0a5-0751-41e0-978d-8670a01239f6_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, shares authorized (in shares) </link:label>
<link:label id="lab_us-gaap_CommonStockSharesAuthorized_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Shares Authorized </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesAuthorized"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesAuthorized" xlink:to="lab_us-gaap_CommonStockSharesAuthorized" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_34cf834f-592f-44d7-806e-1b4af81fa960_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of term loans </link:label>
<link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_f750e56a-fa6c-4b1d-b1ee-263d5f38cfb8_terseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of secured debt </link:label>
<link:label id="lab_us-gaap_RepaymentsOfSecuredDebt_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Secured Debt </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfSecuredDebt" xlink:to="lab_us-gaap_RepaymentsOfSecuredDebt" xlink:type="arc" order="1"/>
<link:label id="lab_srt_TitleOfIndividualAxis_86ddc3a6-006f-4e00-8d32-45c9378f84fb_terseLabel_en-US" xlink:label="lab_srt_TitleOfIndividualAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of Individual [Axis] </link:label>
<link:label id="lab_srt_TitleOfIndividualAxis_label_en-US" xlink:label="lab_srt_TitleOfIndividualAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of Individual [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_TitleOfIndividualAxis" xlink:to="lab_srt_TitleOfIndividualAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dei_DocumentType_4e1f6a32-d069-4c81-b8be-ac740929d509_terseLabel_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Type </link:label>
<link:label id="lab_dei_DocumentType_label_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Type </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentType"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentType" xlink:to="lab_dei_DocumentType" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract_50a40ef8-6bfe-4352-b972-444feae33fe9_terseLabel_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted-Average Remaining Contractual Life (Years) </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract_label_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options,Weighted Average Contractual Term [Abstract] </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract_documentation_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options,Weighted Average Contractual Term [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract" xlink:href="dco-20211231.xsd#dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract" xlink:to="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsWeightedAverageContractualTermAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock_9dcfe177-39a1-4e52-b353-993f9ddc15b0_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Restricted Stock Units Activity </link:label>
<link:label id="lab_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_srt_ProductsAndServicesDomain_0336ebeb-ae99-4744-bcf0-9656f5110aff_terseLabel_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Product and Service [Domain] </link:label>
<link:label id="lab_srt_ProductsAndServicesDomain_label_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Product and Service [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ProductsAndServicesDomain" xlink:to="lab_srt_ProductsAndServicesDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0f2bd145-d0ef-43a6-8793-2ca935f9ac4e_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award [Line Items] </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevolvingCreditFacilityMember_befb82c4-0863-41bc-9500-7ea587a7c227_terseLabel_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revolving Credit Facility </link:label>
<link:label id="lab_us-gaap_RevolvingCreditFacilityMember_label_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revolving Credit Facility [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevolvingCreditFacilityMember" xlink:to="lab_us-gaap_RevolvingCreditFacilityMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_b0397bf7-3261-49a6-be2a-9a78d8c42af1_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Valuation Allowance on Deferred Tax Assets </link:label>
<link:label id="lab_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_label_en-US" xlink:label="lab_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:to="lab_us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LeaseCostTableTextBlock_91d62333-125d-445d-99d1-2c849724cc0d_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Lease, Cost </link:label>
<link:label id="lab_us-gaap_LeaseCostTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Cost [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCostTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LeaseCostTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseCostTableTextBlock" xlink:to="lab_us-gaap_LeaseCostTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent_f093065d-b632-4189-aab6-f8bb9f1a0497_terseLabel_en-US" xlink:label="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liability for labarge deferred compensation plan </link:label>
<link:label id="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent_label_en-US" xlink:label="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension And Other Postretirement Defined Benefit Plans Accrued Employees Compensation And Withholdings Current And Noncurrent </link:label>
<link:label id="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent_documentation_en-US" xlink:label="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension And Other Postretirement Defined Benefit Plans Accrued Employees Compensation And Withholdings Current And Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:href="dco-20211231.xsd#dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:to="lab_dco_PensionAndOtherPostretirementDefinedBenefitPlansAccruedEmployeesCompensationAndWithholdingsCurrentAndNoncurrent" xlink:type="arc" order="1"/>
<link:label id="lab_srt_StatementGeographicalAxis_dbbd419e-7b38-41ca-98cd-acbb30c5356a_terseLabel_en-US" xlink:label="lab_srt_StatementGeographicalAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Axis] </link:label>
<link:label id="lab_srt_StatementGeographicalAxis_label_en-US" xlink:label="lab_srt_StatementGeographicalAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_StatementGeographicalAxis" xlink:to="lab_srt_StatementGeographicalAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StateAndLocalJurisdictionMember_023aed48-510d-4883-b4af-8c0abfebc936_terseLabel_en-US" xlink:label="lab_us-gaap_StateAndLocalJurisdictionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> State </link:label>
<link:label id="lab_us-gaap_StateAndLocalJurisdictionMember_label_en-US" xlink:label="lab_us-gaap_StateAndLocalJurisdictionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> State and Local Jurisdiction [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StateAndLocalJurisdictionMember" xlink:to="lab_us-gaap_StateAndLocalJurisdictionMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_VestingDomain_66c35f0c-3018-4a8a-b6e3-a83604f299b5_terseLabel_en-US" xlink:label="lab_us-gaap_VestingDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vesting [Domain] </link:label>
<link:label id="lab_us-gaap_VestingDomain_label_en-US" xlink:label="lab_us-gaap_VestingDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vesting [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VestingDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VestingDomain" xlink:to="lab_us-gaap_VestingDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongtermDebtWeightedAverageInterestRate_e3f650cd-8df8-4bf1-8d23-55f8a4f806d1_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted-average interest rate </link:label>
<link:label id="lab_us-gaap_LongtermDebtWeightedAverageInterestRate_label_en-US" xlink:label="lab_us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Weighted Average Interest Rate, at Point in Time </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtWeightedAverageInterestRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:to="lab_us-gaap_LongtermDebtWeightedAverageInterestRate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_ade5e6d8-147f-45bb-be76-3bd30eade02e_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of actuarial loss - total before tax </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LockheedMartinMember_e4498e82-3128-40c5-b922-f269a5bf3d28_terseLabel_en-US" xlink:label="lab_dco_LockheedMartinMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lockheed Martin </link:label>
<link:label id="lab_dco_LockheedMartinMember_label_en-US" xlink:label="lab_dco_LockheedMartinMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lockheed Martin [Member] </link:label>
<link:label id="lab_dco_LockheedMartinMember_documentation_en-US" xlink:label="lab_dco_LockheedMartinMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lockheed Martin [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LockheedMartinMember" xlink:href="dco-20211231.xsd#dco_LockheedMartinMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LockheedMartinMember" xlink:to="lab_dco_LockheedMartinMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_b984c0c9-88e9-45c4-8a9f-a6f217e66e59_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash (Used in) Provided by Financing Activities </link:label>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_00461992-1277-47da-a184-414fe979b24a_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted-Average Number of Shares Outstanding </link:label>
<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Diluted [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:to="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_77843de7-b03a-4a3b-abc3-a58dfeef06f4_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Option vesting term </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ContractRenewalMember_499c18de-41a7-4a73-9a66-c9eef77a0986_terseLabel_en-US" xlink:label="lab_dco_ContractRenewalMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract renewal </link:label>
<link:label id="lab_dco_ContractRenewalMember_label_en-US" xlink:label="lab_dco_ContractRenewalMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract Renewal [Member] </link:label>
<link:label id="lab_dco_ContractRenewalMember_documentation_en-US" xlink:label="lab_dco_ContractRenewalMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract Renewal [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ContractRenewalMember" xlink:href="dco-20211231.xsd#dco_ContractRenewalMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ContractRenewalMember" xlink:to="lab_dco_ContractRenewalMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset_a9fd5bca-d66b-4a1c-930d-1401b61224a4_negatedLabel_en-US" xlink:label="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease right-of-use assets </link:label>
<link:label id="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset_label_en-US" xlink:label="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Right-of-Use Asset </link:label>
<link:label id="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset_documentation_en-US" xlink:label="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Right-of-Use Asset </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxLiabilitiesRightOfUseAsset" xlink:href="dco-20211231.xsd#dco_DeferredTaxLiabilitiesRightOfUseAsset"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DeferredTaxLiabilitiesRightOfUseAsset" xlink:to="lab_dco_DeferredTaxLiabilitiesRightOfUseAsset" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock_e41a4936-0bfe-4f95-a4a8-cf317892dbf4_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finance Lease, Liability, Maturity </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, Fiscal Year Maturity [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock" xlink:to="lab_us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RestructuringCharges_831750eb-b230-4e73-b10a-82300e1a5d83_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCharges" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restructuring Charges </link:label>
<link:label id="lab_us-gaap_RestructuringCharges_1ea79d20-b011-4ab3-83b9-0bc78c0a2b42_verboseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCharges" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restructuring charges </link:label>
<link:label id="lab_us-gaap_RestructuringCharges_label_en-US" xlink:label="lab_us-gaap_RestructuringCharges" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restructuring Charges </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringCharges"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringCharges" xlink:to="lab_us-gaap_RestructuringCharges" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ConcentrationRiskByTypeAxis_10797e75-c767-4325-9a3b-b044d47a5a6f_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Type [Axis] </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskByTypeAxis_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis" xlink:to="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract_a7ac0273-7483-4876-b699-8359bd343a92_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment [Abstract] </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" xlink:to="lab_us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_add8bf3c-687b-4067-b974-05bd4d8a053f_terseLabel_en-US" xlink:label="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based offering period </link:label>
<link:label id="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_label_en-US" xlink:label="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Offering Period </link:label>
<link:label id="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_documentation_en-US" xlink:label="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Offering Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:href="dco-20211231.xsd#dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:to="lab_dco_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_26d08033-d35c-44d9-92aa-274e11a510d8_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year Three </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesAbstract_7474f3f8-d8d7-4341-9a08-defec350e7d9_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred tax liabilities: </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesAbstract_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Gross [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationsPolicy_fa038cb6-384b-4f9d-b6cd-29ef678d4863_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combinations </link:label>
<link:label id="lab_us-gaap_BusinessCombinationsPolicy_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combinations Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationsPolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationsPolicy" xlink:to="lab_us-gaap_BusinessCombinationsPolicy" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesNetAbstract_ddfbcf83-8a09-4603-82e7-5c74f027e3d8_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Net [Abstract] </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesNetAbstract_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Net [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNetAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dei_DocumentPeriodEndDate_d7d2cf4e-8d32-4177-8b7d-d56b655dc893_terseLabel_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Period End Date </link:label>
<link:label id="lab_dei_DocumentPeriodEndDate_label_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Period End Date </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentPeriodEndDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentPeriodEndDate" xlink:to="lab_dei_DocumentPeriodEndDate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ConcentrationRiskBenchmarkDomain_46266dc7-128e-49b4-a453-e5fc7ed7ff49_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Benchmark [Domain] </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskBenchmarkDomain_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Benchmark [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="lab_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FixedIncomeSecuritiesMember_de582748-628a-4fb9-a243-6bb64898addf_terseLabel_en-US" xlink:label="lab_us-gaap_FixedIncomeSecuritiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed income securities </link:label>
<link:label id="lab_us-gaap_FixedIncomeSecuritiesMember_label_en-US" xlink:label="lab_us-gaap_FixedIncomeSecuritiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fixed Income Securities [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedIncomeSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FixedIncomeSecuritiesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FixedIncomeSecuritiesMember" xlink:to="lab_us-gaap_FixedIncomeSecuritiesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_d3b3df23-7b42-4c17-96d0-0670bb591b7c_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Stock Options </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_1986e1f5-fc46-4d7d-84fd-01d5558dd6ef_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> State income taxes (net of federal benefit) </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_1c18e8c1-6744-4612-8a84-dbff045373c7_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> State </link:label>
<link:label id="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred State and Local Income Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentTextBlock_5bbc3872-aea3-4102-b5a0-2f359761219f_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Property and Equipment </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentTextBlock_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_GovernmentGrantExpense_73490bc8-fc71-4e35-bc83-6fac4a3d72f5_terseLabel_en-US" xlink:label="lab_dco_GovernmentGrantExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Government grant expense </link:label>
<link:label id="lab_dco_GovernmentGrantExpense_label_en-US" xlink:label="lab_dco_GovernmentGrantExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Government Grant Expense </link:label>
<link:label id="lab_dco_GovernmentGrantExpense_documentation_en-US" xlink:label="lab_dco_GovernmentGrantExpense" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Government Grant Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_GovernmentGrantExpense" xlink:href="dco-20211231.xsd#dco_GovernmentGrantExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_GovernmentGrantExpense" xlink:to="lab_dco_GovernmentGrantExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeStatementLocationDomain_1a8853c5-cb83-4121-9961-c1acaf14e36c_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Domain] </link:label>
<link:label id="lab_us-gaap_IncomeStatementLocationDomain_label_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementLocationDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementLocationDomain" xlink:to="lab_us-gaap_IncomeStatementLocationDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_34abdc10-fd70-4443-908c-c0a64e6f40c4_terseLabel_en-US" xlink:label="lab_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-cash activities: </link:label>
<link:label id="lab_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:to="lab_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_24c8aec8-5256-452a-8c24-47f10322e714_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of actuarial (loss) gain, tax </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_abcf8591-ef8d-4c8d-bca9-36263062cf75_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax benefit </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentNet_4104259a-76ef-41f0-8977-8a66e6856f92_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property and Equipment, Net </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentNet_4951e3d1-3580-4e85-941d-b3a57a28868d_totalLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentNet_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LossContingencyNumberOfBuildingsAffected_dd3da066-29ad-41f0-8ea2-81f7517a0cb0_terseLabel_en-US" xlink:label="lab_dco_LossContingencyNumberOfBuildingsAffected" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of buildings </link:label>
<link:label id="lab_dco_LossContingencyNumberOfBuildingsAffected_label_en-US" xlink:label="lab_dco_LossContingencyNumberOfBuildingsAffected" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency, Number of Buildings Affected </link:label>
<link:label id="lab_dco_LossContingencyNumberOfBuildingsAffected_documentation_en-US" xlink:label="lab_dco_LossContingencyNumberOfBuildingsAffected" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency, Number of Buildings Affected </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LossContingencyNumberOfBuildingsAffected" xlink:href="dco-20211231.xsd#dco_LossContingencyNumberOfBuildingsAffected"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LossContingencyNumberOfBuildingsAffected" xlink:to="lab_dco_LossContingencyNumberOfBuildingsAffected" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_aa84051c-b38e-4c45-b0d7-69652b57a79a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Future Amortization Expense </link:label>
<link:label id="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:to="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EarningsPerShareAbstract_d58b109a-974e-4dbd-8f0e-5af07dc2d28c_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share </link:label>
<link:label id="lab_us-gaap_EarningsPerShareAbstract_9f750766-479b-4df9-96e1-e73be1b333ab_verboseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings per share </link:label>
<link:label id="lab_us-gaap_EarningsPerShareAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareAbstract" xlink:to="lab_us-gaap_EarningsPerShareAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentGross_637143e4-14a6-465f-b1fe-ba9bd3264c0a_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, plant and equipment, gross </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentGross_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentGross" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentGross" xlink:type="arc" order="1"/>
<link:label id="lab_dco_AccruedGovernmentGrant_aac11402-539f-429f-ab41-8b03b217fa96_terseLabel_en-US" xlink:label="lab_dco_AccruedGovernmentGrant" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued government grant </link:label>
<link:label id="lab_dco_AccruedGovernmentGrant_label_en-US" xlink:label="lab_dco_AccruedGovernmentGrant" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Government Grant </link:label>
<link:label id="lab_dco_AccruedGovernmentGrant_documentation_en-US" xlink:label="lab_dco_AccruedGovernmentGrant" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Government Grant </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_AccruedGovernmentGrant" xlink:href="dco-20211231.xsd#dco_AccruedGovernmentGrant"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_AccruedGovernmentGrant" xlink:to="lab_dco_AccruedGovernmentGrant" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerMember_847183d3-a573-42c0-8c79-22652211cd61_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue from Contract with Customer Benchmark </link:label>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerMember_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue from Contract with Customer Benchmark [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerMember" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationPercentage_a74423a3-ecf3-44e1-94ea-7e7e40b6191e_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining performance obligation, percentage </link:label>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationPercentage_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Percentage </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InventoryFinishedGoods_f5c1c91c-fcd6-4656-80ea-db99c8bc7408_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryFinishedGoods" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finished goods </link:label>
<link:label id="lab_us-gaap_InventoryFinishedGoods_label_en-US" xlink:label="lab_us-gaap_InventoryFinishedGoods" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory, Finished Goods, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoods" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryFinishedGoods"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryFinishedGoods" xlink:to="lab_us-gaap_InventoryFinishedGoods" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LossContingencyAccrualAtCarryingValue_69967680-6a0f-4173-bf78-8a394d1e6ac9_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingencyAccrualAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reserve for estimated liability </link:label>
<link:label id="lab_us-gaap_LossContingencyAccrualAtCarryingValue_label_en-US" xlink:label="lab_us-gaap_LossContingencyAccrualAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency Accrual </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyAccrualAtCarryingValue" xlink:to="lab_us-gaap_LossContingencyAccrualAtCarryingValue" xlink:type="arc" order="1"/>
<link:label id="lab_dco_NumberOfUnfundedSupplementalRetirementPlans_b74c4526-9fc0-4a9d-b620-72dc9bd16e27_terseLabel_en-US" xlink:label="lab_dco_NumberOfUnfundedSupplementalRetirementPlans" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of unfunded supplemental retirement plans </link:label>
<link:label id="lab_dco_NumberOfUnfundedSupplementalRetirementPlans_label_en-US" xlink:label="lab_dco_NumberOfUnfundedSupplementalRetirementPlans" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Unfunded Supplemental Retirement Plans </link:label>
<link:label id="lab_dco_NumberOfUnfundedSupplementalRetirementPlans_documentation_en-US" xlink:label="lab_dco_NumberOfUnfundedSupplementalRetirementPlans" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Unfunded Supplemental Retirement Plans </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_NumberOfUnfundedSupplementalRetirementPlans" xlink:href="dco-20211231.xsd#dco_NumberOfUnfundedSupplementalRetirementPlans"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_NumberOfUnfundedSupplementalRetirementPlans" xlink:to="lab_dco_NumberOfUnfundedSupplementalRetirementPlans" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_a96c3b16-a671-4309-9192-60b1ad398f18_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_9bdc067a-a84d-41ac-8516-280689eba72f_periodEndLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending balance (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price </link:label>
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<link:label id="lab_dei_EntityCurrentReportingStatus_1ac35243-8908-402b-b7de-b728ca1193ec_terseLabel_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Current Reporting Status </link:label>
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<link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_4acd0d24-fb40-43f4-b387-e63e98982b85_periodStartLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair value of plan assets at beginning of year </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_d9632991-0ba6-4ef2-8fd9-e07d539f997c_periodEndLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair value of plan assets at end of year </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_0479d155-5943-4e1b-8745-b155fee35fc0_totalLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total fair value of plan assets </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Amount </link:label>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d473c1ef-b02a-4738-a03b-c83d958efba2_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Grant Date Fair Value </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] </link:label>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations_befc370f-877c-4d63-a994-a522be3a844c_totalLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective income tax rate </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
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<link:label id="lab_us-gaap_LossContingencyEstimateOfPossibleLoss_b2eb39af-ed5d-46c7-9236-105de33c0bf1_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Possible loss </link:label>
<link:label id="lab_us-gaap_LossContingencyEstimateOfPossibleLoss_label_en-US" xlink:label="lab_us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency, Estimate of Possible Loss </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:to="lab_us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SignificantAccountingPoliciesLineItems_a12e13f8-9b31-4331-ab03-74275cd04449_terseLabel_en-US" xlink:label="lab_dco_SignificantAccountingPoliciesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Line Items] </link:label>
<link:label id="lab_dco_SignificantAccountingPoliciesLineItems_label_en-US" xlink:label="lab_dco_SignificantAccountingPoliciesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Line Items] </link:label>
<link:label id="lab_dco_SignificantAccountingPoliciesLineItems_documentation_en-US" xlink:label="lab_dco_SignificantAccountingPoliciesLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SignificantAccountingPoliciesLineItems" xlink:href="dco-20211231.xsd#dco_SignificantAccountingPoliciesLineItems"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_131ab437-fac8-41c0-8cb2-4ae756e6127f_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated employer Contribution to pension plan in next fiscal year </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear"/>
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<link:label id="lab_us-gaap_AmortizationOfFinancingCosts_82d141e4-d9a0-40a0-9b15-65476a0143b2_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of debt issuance costs </link:label>
<link:label id="lab_us-gaap_AmortizationOfFinancingCosts_label_en-US" xlink:label="lab_us-gaap_AmortizationOfFinancingCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization of Debt Issuance Costs </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfFinancingCosts"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue_6174d691-da94-459d-a4b2-ed415fdc35df_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate intrinsic value </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue"/>
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<link:label id="lab_us-gaap_ContractWithCustomerAssetNetCurrent_68861940-0d93-4a8f-8cae-689baa6fa9e1_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetNetCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract assets </link:label>
<link:label id="lab_us-gaap_ContractWithCustomerAssetNetCurrent_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetNetCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract with Customer, Asset, after Allowance for Credit Loss, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerAssetNetCurrent"/>
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<link:label id="lab_us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock_702adf71-2477-40d1-87d4-3999c79204d0_terseLabel_en-US" xlink:label="lab_us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Concentration Risk by Major Customers </link:label>
<link:label id="lab_us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock_label_en-US" xlink:label="lab_us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedules of Concentration of Risk, by Risk Factor [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_42617ee6-6840-4f77-b29e-3aa7e5097924_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Shares reserved for future issuance (in shares) </link:label>
<link:label id="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_label_en-US" xlink:label="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Capital Shares Reserved for Future Issuance </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
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<link:label id="lab_us-gaap_LeasesAbstract_004ed705-92d3-4506-9471-357888393932_terseLabel_en-US" xlink:label="lab_us-gaap_LeasesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Leases [Abstract] </link:label>
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<link:label id="lab_us-gaap_IncomeTaxPolicyTextBlock_7d6d2fa0-ac97-458e-80c5-c6887f5591b8_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Taxes </link:label>
<link:label id="lab_us-gaap_IncomeTaxPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_IncomeTaxPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock"/>
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<link:label id="lab_us-gaap_LondonInterbankOfferedRateLIBORMember_fabb2c9b-2b62-42af-a9b6-cb6ba37bff49_terseLabel_en-US" xlink:label="lab_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> LIBOR Rate </link:label>
<link:label id="lab_us-gaap_LondonInterbankOfferedRateLIBORMember_label_en-US" xlink:label="lab_us-gaap_LondonInterbankOfferedRateLIBORMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> London Interbank Offered Rate (LIBOR) [Member] </link:label>
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<link:label id="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock_503f6ede-c0b6-4bd7-bd43-18b411327f60_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Performance-based Units Activity </link:label>
<link:label id="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Nonvested Performance-based Units Activity [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityAddressPostalZipCode_19bf8c47-869c-4aa4-9f98-92e145ac0d28_terseLabel_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Postal Zip Code </link:label>
<link:label id="lab_dei_EntityAddressPostalZipCode_label_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Postal Zip Code </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressPostalZipCode"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressPostalZipCode" xlink:to="lab_dei_EntityAddressPostalZipCode" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_19d4d8f4-b9f0-421a-a182-e38ed2cd1e8a_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue Recognition </link:label>
<link:label id="lab_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue from Contract with Customer [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:to="lab_us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent_f41274c1-79a3-4c78-a172-89ff8698c311_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Foreign derived intangible income deduction </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Transition Tax on Accumulated Foreign Earnings, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActOf2017TransitionTaxOnAccumulatedForeignEarningsPercent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_8195ba82-b48b-4075-94ed-b562483b987f_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Diluted (in shares) </link:label>
<link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_c88b01bb-2fb7-4ee7-9532-ee3cac0af710_totalLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Diluted weighted-average common shares outstanding (in shares) </link:label>
<link:label id="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Diluted </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="lab_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeTaxDisclosureTextBlock_59067855-8079-4735-a051-953a57b7007b_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Taxes </link:label>
<link:label id="lab_us-gaap_IncomeTaxDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Tax Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongtermDebtTypeAxis_6d0d8ae4-3bb9-429f-8ea2-d9b230ff5b39_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Type [Axis] </link:label>
<link:label id="lab_us-gaap_LongtermDebtTypeAxis_label_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongtermDebtTypeAxis" xlink:to="lab_us-gaap_LongtermDebtTypeAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_b38f8198-0b95-4327-a78f-769f0b4c834c_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Option Activity </link:label>
<link:label id="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Option, Activity [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_d6ef7b99-47b3-4344-9a16-a302f8bc12e2_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Spread on variable rate </link:label>
<link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Basis Spread on Variable Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:to="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_e0af361d-f268-467c-ab3b-9c296901528a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Components of Net Periodic Pension Cost </link:label>
<link:label id="lab_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Net Benefit Costs [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfNetBenefitCostsTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_GoodwillAndOtherIntangibleAssets_34ce3dc8-e073-4ab3-a732-ee51caf50ad4_terseLabel_en-US" xlink:label="lab_dco_GoodwillAndOtherIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill and Intangibles </link:label>
<link:label id="lab_dco_GoodwillAndOtherIntangibleAssets_label_en-US" xlink:label="lab_dco_GoodwillAndOtherIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Other Intangible Assets </link:label>
<link:label id="lab_dco_GoodwillAndOtherIntangibleAssets_documentation_en-US" xlink:label="lab_dco_GoodwillAndOtherIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Other Intangible Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_GoodwillAndOtherIntangibleAssets" xlink:href="dco-20211231.xsd#dco_GoodwillAndOtherIntangibleAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_GoodwillAndOtherIntangibleAssets" xlink:to="lab_dco_GoodwillAndOtherIntangibleAssets" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_cab176f9-37fa-49a1-9b5e-3b3f3c4d7e26_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Cash Flows [Abstract] </link:label>
<link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Cash Flows [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:to="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_b796609c-a93a-4f9a-856d-385defd49ad9_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Options vested (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CreditFacilityAxis_0112a81d-023d-4236-b2da-6bd94e1f847a_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Axis] </link:label>
<link:label id="lab_us-gaap_CreditFacilityAxis_label_en-US" xlink:label="lab_us-gaap_CreditFacilityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityAxis" xlink:to="lab_us-gaap_CreditFacilityAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_76552480-3509-4539-a253-3b781c8c44e1_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Major Class Name [Domain] </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Major Class Name [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityAddressAddressLine1_277219f6-8709-4b9d-9286-f3fb75dea324_terseLabel_en-US" xlink:label="lab_dei_EntityAddressAddressLine1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Address Line One </link:label>
<link:label id="lab_dei_EntityAddressAddressLine1_label_en-US" xlink:label="lab_dei_EntityAddressAddressLine1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, Address Line One </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressAddressLine1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityAddressAddressLine1" xlink:to="lab_dei_EntityAddressAddressLine1" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_1f11168c-e4a0-410c-bd0e-2ad58c61a130_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less accumulated depreciation </link:label>
<link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_6b01a3ed-9c51-49b9-8786-4c0d840944f6_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee stock purchase plan </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued During Period, Value, Employee Stock Purchase Plan </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts_9b93cd0b-9cea-4b07-9174-68c99ed8daa2_terseLabel_en-US" xlink:label="lab_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Allowance for Credit Losses </link:label>
<link:label id="lab_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts_label_en-US" xlink:label="lab_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Financing Receivable, Allowance for Credit Losses, Policy for Uncollectible Amounts [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts" xlink:to="lab_us-gaap_FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_e3bcc1a5-9e50-4e8c-8a57-8114b8c90153_terseLabel_en-US" xlink:label="lab_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt issuance costs, line of credit arrangements </link:label>
<link:label id="lab_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet_label_en-US" xlink:label="lab_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Issuance Costs, Line of Credit Arrangements, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet" xlink:to="lab_us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_b579a286-c161-42b0-ad56-1231f49a64ec_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other current assets </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
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<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_19da3d96-fa6c-47ea-a65a-62f5040eba30_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash Flows from Operating Activities </link:label>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityShellCompany_5a4931ec-abf2-44f5-a0f1-167196c3019e_terseLabel_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Shell Company </link:label>
<link:label id="lab_dei_EntityShellCompany_label_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Shell Company </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityShellCompany"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityShellCompany" xlink:to="lab_dei_EntityShellCompany" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_4f72122e-c8a2-4479-b315-96c179a46b8a_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected term (in months) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LiabilitiesCurrent_a30d038b-ff52-43ca-bfec-124a8c2d2bc7_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Current Liabilities </link:label>
<link:label id="lab_us-gaap_LiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrent" xlink:to="lab_us-gaap_LiabilitiesCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EmployeeStockMember_da9e8d55-b34d-46cc-aae5-785fa10e9560_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee Stock </link:label>
<link:label id="lab_us-gaap_EmployeeStockMember_label_en-US" xlink:label="lab_us-gaap_EmployeeStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee Stock [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeStockMember" xlink:to="lab_us-gaap_EmployeeStockMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanOtherInvestmentsMember_adf02b42-0ee8-4a49-ad75-c5f94a5ea1ab_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanOtherInvestmentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other investments </link:label>
<link:label id="lab_dco_DefinedBenefitPlanOtherInvestmentsMember_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanOtherInvestmentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Other Investments [Member] </link:label>
<link:label id="lab_dco_DefinedBenefitPlanOtherInvestmentsMember_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanOtherInvestmentsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Other Investments [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanOtherInvestmentsMember" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanOtherInvestmentsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanOtherInvestmentsMember" xlink:to="lab_dco_DefinedBenefitPlanOtherInvestmentsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LossContingenciesTable_2e1fb175-283c-4f4a-9708-c95986fbfec1_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingenciesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingencies [Table] </link:label>
<link:label id="lab_us-gaap_LossContingenciesTable_label_en-US" xlink:label="lab_us-gaap_LossContingenciesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingencies [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingenciesTable" xlink:to="lab_us-gaap_LossContingenciesTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_b332c80f-edc6-461c-bd2c-01a7bee37a02_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock_5dc6a7f1-7b87-47fb-bfbd-44401ce1151a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Obligation and Funded Status of Defined Benefit Pension Plan and Retirement Plan </link:label>
<link:label id="lab_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dei_CurrentFiscalYearEndDate_63f95037-54fc-49da-a273-750be4905c1a_terseLabel_en-US" xlink:label="lab_dei_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Fiscal Year End Date </link:label>
<link:label id="lab_dei_CurrentFiscalYearEndDate_label_en-US" xlink:label="lab_dei_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Fiscal Year End Date </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_CurrentFiscalYearEndDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CurrentFiscalYearEndDate" xlink:to="lab_dei_CurrentFiscalYearEndDate" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LocationOneMember_c8aada23-a150-4979-837a-d74c2e1f8d06_terseLabel_en-US" xlink:label="lab_dco_LocationOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> El Mirage and Monrovia, California </link:label>
<link:label id="lab_dco_LocationOneMember_label_en-US" xlink:label="lab_dco_LocationOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Location One [Member] </link:label>
<link:label id="lab_dco_LocationOneMember_documentation_en-US" xlink:label="lab_dco_LocationOneMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Location 1 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LocationOneMember" xlink:href="dco-20211231.xsd#dco_LocationOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LocationOneMember" xlink:to="lab_dco_LocationOneMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses_3c650ae2-40e9-4019-99f0-4de41a6617d2_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset (gain) loss </link:label>
<link:label id="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Amortization Of Unrecognized Gains Losses </link:label>
<link:label id="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Amortization Of Unrecognized Gains Losses </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses" xlink:to="lab_dco_DefinedBenefitPlanAmortizationOfUnrecognizedGainsLosses" xlink:type="arc" order="1"/>
<link:label id="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized_616a6961-7541-4408-8d3c-a571f16d3890_terseLabel_en-US" xlink:label="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating loss carryforward not expected to be realized under ASC subtopic 740-10 </link:label>
<link:label id="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized_label_en-US" xlink:label="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Loss Carryforward, Not Expected to be Realized </link:label>
<link:label id="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized_documentation_en-US" xlink:label="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Loss Carryforward, Not Expected to be Realized </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_OperatingLossCarryforwardNotExpectedtobeRealized" xlink:href="dco-20211231.xsd#dco_OperatingLossCarryforwardNotExpectedtobeRealized"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_OperatingLossCarryforwardNotExpectedtobeRealized" xlink:to="lab_dco_OperatingLossCarryforwardNotExpectedtobeRealized" xlink:type="arc" order="1"/>
<link:label id="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member_339eeb47-96e0-41b2-80a5-37252faade57_terseLabel_en-US" xlink:label="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2018 Revolving Credit Facility </link:label>
<link:label id="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member_label_en-US" xlink:label="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New 2018 Revolving Credit Facility Maturing November 21, 2023 [Member] </link:label>
<link:label id="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member_documentation_en-US" xlink:label="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New 2018 Revolving Credit Facility Maturing November 21, 2023 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member" xlink:href="dco-20211231.xsd#dco_New2018RevolvingCreditFacilityMaturingNovember212023Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member" xlink:to="lab_dco_New2018RevolvingCreditFacilityMaturingNovember212023Member" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StatementTable_9681e817-f676-4275-a457-9938ec19b626_terseLabel_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Table] </link:label>
<link:label id="lab_us-gaap_StatementTable_label_en-US" xlink:label="lab_us-gaap_StatementTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementTable" xlink:to="lab_us-gaap_StatementTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_7a9da2a1-8b39-4ef3-af7d-02780151733b_terseLabel_en-US" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Changes in Accounting Policies and Recent Accounting Pronouncements </link:label>
<link:label id="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Accounting Pronouncements, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsOther_7bc5f30b-d6ba-4900-b5a6-856caf882c19_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsOther_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Other </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsOther" xlink:to="lab_us-gaap_DeferredTaxAssetsOther" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_0c5303a4-3e47-40c2-846a-20923df6e07f_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment, Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:to="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:type="arc" order="1"/>
<link:label id="lab_srt_RangeAxis_7c03ecbc-c3d9-48e0-a72d-3f6836f46cd1_terseLabel_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Axis] </link:label>
<link:label id="lab_srt_RangeAxis_label_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeAxis" xlink:to="lab_srt_RangeAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable_69bf4325-ab75-40dc-bf66-e978375f212b_terseLabel_en-US" xlink:label="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Benefit Obligations Weighted Average Assumptions [Table] </link:label>
<link:label id="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable_label_en-US" xlink:label="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Benefit Obligations Weighted Average Assumptions [Table] </link:label>
<link:label id="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable_documentation_en-US" xlink:label="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Benefit Obligations Weighted Average Assumptions [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable" xlink:href="dco-20211231.xsd#dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable" xlink:to="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_cc6f3c44-402b-407d-8c13-fa8982b74d4f_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vested (in shares) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_080955ae-14c4-463d-9674-95425e2468ed_totalLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Carrying Amount </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNet_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_Goodwill_7df06428-0e4c-4b5d-bbd2-bd38390164ad_terseLabel_en-US" xlink:label="lab_us-gaap_Goodwill" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill </link:label>
<link:label id="lab_us-gaap_Goodwill_0ae23748-c803-4854-bc7f-23c84156bac4_periodStartLabel_en-US" xlink:label="lab_us-gaap_Goodwill" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill, beginning balance </link:label>
<link:label id="lab_us-gaap_Goodwill_8f49bf85-51cd-485f-ac9a-6d1cd697d13e_periodEndLabel_en-US" xlink:label="lab_us-gaap_Goodwill" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill, ending balance </link:label>
<link:label id="lab_us-gaap_Goodwill_label_en-US" xlink:label="lab_us-gaap_Goodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Goodwill" xlink:to="lab_us-gaap_Goodwill" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_f0342a9d-3cf9-4ecd-8090-79068e260b5c_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and cash equivalents </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Cash and Cash Equivalents [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:to="lab_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_GuaranteesAndIndemnificationsTextBlock_0c07c78f-b50c-4b71-b708-f66c137ee980_terseLabel_en-US" xlink:label="lab_dco_GuaranteesAndIndemnificationsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indemnifications </link:label>
<link:label id="lab_dco_GuaranteesAndIndemnificationsTextBlock_label_en-US" xlink:label="lab_dco_GuaranteesAndIndemnificationsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Guarantees And Indemnifications [Text Block] </link:label>
<link:label id="lab_dco_GuaranteesAndIndemnificationsTextBlock_documentation_en-US" xlink:label="lab_dco_GuaranteesAndIndemnificationsTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Guarantees and Indemnifications. </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_GuaranteesAndIndemnificationsTextBlock" xlink:href="dco-20211231.xsd#dco_GuaranteesAndIndemnificationsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_GuaranteesAndIndemnificationsTextBlock" xlink:to="lab_dco_GuaranteesAndIndemnificationsTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_b5a83c1f-a049-44fa-acf6-8ed8a3037b09_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Forfeited (in shares) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:type="arc" order="1"/>
<link:label id="lab_dco_StructuralSystemsMember_c64826d4-4537-4099-b8db-5a80ef020f1c_terseLabel_en-US" xlink:label="lab_dco_StructuralSystemsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Structural Systems </link:label>
<link:label id="lab_dco_StructuralSystemsMember_label_en-US" xlink:label="lab_dco_StructuralSystemsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Structural Systems [Member] </link:label>
<link:label id="lab_dco_StructuralSystemsMember_documentation_en-US" xlink:label="lab_dco_StructuralSystemsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Structural Systems [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_StructuralSystemsMember" xlink:href="dco-20211231.xsd#dco_StructuralSystemsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_StructuralSystemsMember" xlink:to="lab_dco_StructuralSystemsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfGoodwillTextBlock_ad17c3eb-1410-4db8-a3d6-a6c5db61165a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfGoodwillTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Goodwill </link:label>
<link:label id="lab_us-gaap_ScheduleOfGoodwillTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfGoodwillTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Goodwill [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfGoodwillTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfGoodwillTextBlock" xlink:to="lab_us-gaap_ScheduleOfGoodwillTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_12afe76f-22f8-4bab-9f0e-6f7eedfb3244_terseLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities: </link:label>
<link:label id="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
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<link:label id="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments_e1f4e189-389d-41cd-bf6a-8b76c7a798bd_terseLabel_en-US" xlink:label="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate minimum monthly lease payments </link:label>
<link:label id="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments_label_en-US" xlink:label="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Aggregate Minimum Monthly Lease Payments </link:label>
<link:label id="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments_documentation_en-US" xlink:label="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Aggregate Minimum Monthly Lease Payments </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments" xlink:href="dco-20211231.xsd#dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments" xlink:to="lab_dco_SaleLeasebackTransactionAggregateMinimumMonthlyLeasePayments" xlink:type="arc" order="1"/>
<link:label id="lab_dco_A2020StockIncentivePlanThe2020PlanMember_5e7e5a20-2ffc-4595-bc18-0902e38c28de_terseLabel_en-US" xlink:label="lab_dco_A2020StockIncentivePlanThe2020PlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2020 Plan </link:label>
<link:label id="lab_dco_A2020StockIncentivePlanThe2020PlanMember_label_en-US" xlink:label="lab_dco_A2020StockIncentivePlanThe2020PlanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2020 Stock Incentive Plan (the 2020 Plan) [Member] </link:label>
<link:label id="lab_dco_A2020StockIncentivePlanThe2020PlanMember_documentation_en-US" xlink:label="lab_dco_A2020StockIncentivePlanThe2020PlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2020 Stock Incentive Plan (the 2020 Plan) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_A2020StockIncentivePlanThe2020PlanMember" xlink:href="dco-20211231.xsd#dco_A2020StockIncentivePlanThe2020PlanMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_A2020StockIncentivePlanThe2020PlanMember" xlink:to="lab_dco_A2020StockIncentivePlanThe2020PlanMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLeaseCost_f7e1e9a1-a86c-4aa6-9ae3-7ab75e5b124b_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating leases expense </link:label>
<link:label id="lab_us-gaap_OperatingLeaseCost_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Cost </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseCost"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseCost" xlink:to="lab_us-gaap_OperatingLeaseCost" xlink:type="arc" order="1"/>
<link:label id="lab_dco_IncreaseDecreaseinProductionCostofContract_6d77eaa9-c8d0-43f8-b908-dfd84d5691ca_negatedLabel_en-US" xlink:label="lab_dco_IncreaseDecreaseinProductionCostofContract" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Production cost of contracts </link:label>
<link:label id="lab_dco_IncreaseDecreaseinProductionCostofContract_label_en-US" xlink:label="lab_dco_IncreaseDecreaseinProductionCostofContract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Production Cost of Contract </link:label>
<link:label id="lab_dco_IncreaseDecreaseinProductionCostofContract_documentation_en-US" xlink:label="lab_dco_IncreaseDecreaseinProductionCostofContract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Production Cost of Contract </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_IncreaseDecreaseinProductionCostofContract" xlink:href="dco-20211231.xsd#dco_IncreaseDecreaseinProductionCostofContract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_IncreaseDecreaseinProductionCostofContract" xlink:to="lab_dco_IncreaseDecreaseinProductionCostofContract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_3d26e420-988d-4e0d-80e6-41d3ff97713f_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Forfeited, (in dollars per share) </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
<link:label id="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets_20dc7496-ce1e-44dd-a972-5ca9af2be8ab_totalLabel_en-US" xlink:label="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total assets acquired </link:label>
<link:label id="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets_label_en-US" xlink:label="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination Recognized Identifiable Assets Acquired, Goodwill And Liabilities Assumed Assets </link:label>
<link:label id="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets_documentation_en-US" xlink:label="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination Recognized Identifiable Assets Acquired, Goodwill And Liabilities Assumed Assets. </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets" xlink:href="dco-20211231.xsd#dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets" xlink:to="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedAssets" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_ec85ca29-266e-483a-b33d-158d57274557_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contribution by employee towards defined benefit plan </link:label>
<link:label id="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_label_en-US" xlink:label="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:to="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredIncomeTaxExpenseBenefit_22accff3-5022-4de9-bd8b-af957e6744c4_totalLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred tax expense (benefit) </link:label>
<link:label id="lab_us-gaap_DeferredIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy_d734c820-3234-4c73-90eb-057330eb90e7_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents </link:label>
<link:label id="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:to="lab_us-gaap_CashAndCashEquivalentsUnrestrictedCashAndCashEquivalentsPolicy" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_HedgingDesignationDomain_f84cb05b-45e2-42f3-ba29-8716046991e0_terseLabel_en-US" xlink:label="lab_us-gaap_HedgingDesignationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Domain] </link:label>
<link:label id="lab_us-gaap_HedgingDesignationDomain_label_en-US" xlink:label="lab_us-gaap_HedgingDesignationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_HedgingDesignationDomain" xlink:to="lab_us-gaap_HedgingDesignationDomain" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25_596c8a3c-e1f4-4fb3-83e3-48103072872c_terseLabel_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of excess cash flow payment when leverage ratio is greater than 3.25 </link:label>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25_label_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Percentage of Excess Cash Flow Payment When Leverage Ratio is Greater than 3.25 </link:label>
<link:label id="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25_documentation_en-US" xlink:label="lab_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Percentage of Excess Cash Flow Payment When Leverage Ratio is Greater than 3.25 </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25" xlink:href="dco-20211231.xsd#dco_DebtInstrumentPercentageofExcessCashFlowPaymentWhenLeverageRatioisGreaterthan3.25"/>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_ed0ae99e-f233-4e39-ac88-bd80366e1b07_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statutory federal income tax rate </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InventoryWorkInProcess_89cca2ec-9cb2-4fdc-a314-e45662e42d75_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryWorkInProcess" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Work in process </link:label>
<link:label id="lab_us-gaap_InventoryWorkInProcess_label_en-US" xlink:label="lab_us-gaap_InventoryWorkInProcess" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory, Work in Process, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcess" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryWorkInProcess"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryWorkInProcess" xlink:to="lab_us-gaap_InventoryWorkInProcess" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EarningsPerSharePolicyTextBlock_7f995eae-faa8-4f51-9a06-a13f2242edbe_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings per Share </link:label>
<link:label id="lab_us-gaap_EarningsPerSharePolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerSharePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="lab_us-gaap_EarningsPerSharePolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_TrademarksAndTradeNamesMember_3fa44005-85cc-42d0-bdaf-af372dddc12d_terseLabel_en-US" xlink:label="lab_us-gaap_TrademarksAndTradeNamesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trade names and trademarks </link:label>
<link:label id="lab_us-gaap_TrademarksAndTradeNamesMember_label_en-US" xlink:label="lab_us-gaap_TrademarksAndTradeNamesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trademarks and Trade Names [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TrademarksAndTradeNamesMember" xlink:to="lab_us-gaap_TrademarksAndTradeNamesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c0f910fd-5123-4c4a-9d07-4e163006c804_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Hierarchy and NAV [Domain] </link:label>
<link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value Hierarchy and NAV [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NetIncomeLoss_84b3372a-aee4-4bae-a303-2cbf085f7690_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income </link:label>
<link:label id="lab_us-gaap_NetIncomeLoss_68c89912-3d5c-4ecf-8257-8e5e36f807c7_verboseLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income </link:label>
<link:label id="lab_us-gaap_NetIncomeLoss_8f3505c7-4eff-438d-813d-877af9c45265_netLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net income </link:label>
<link:label id="lab_us-gaap_NetIncomeLoss_label_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Income (Loss) Attributable to Parent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLoss" xlink:to="lab_us-gaap_NetIncomeLoss" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLeaseRightOfUseAsset_3077902a-5dc6-4de0-809a-842f49e5bf5a_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease Right-of-Use Assets </link:label>
<link:label id="lab_us-gaap_OperatingLeaseRightOfUseAsset_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Right-of-Use Asset </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="lab_us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess_f659f792-ee58-4c7d-91a5-f2a8b390fc3f_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Excess of accumulated benefit obligation over fair value of plan assets </link:label>
<link:label id="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Amount in Excess </link:label>
<link:label id="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Amount in Excess </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess" xlink:to="lab_dco_DefinedBenefitPlanPlanswithBenefitObligationsinExcessofPlanAssetsAmountinExcess" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions_05d2bf0c-2748-4bba-908d-14b87968cb51_terseLabel_en-US" xlink:label="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Provision for matching and profit sharing contribution </link:label>
<link:label id="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions_label_en-US" xlink:label="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan, Provision for Matching and Profit Sharing Contributions </link:label>
<link:label id="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions_documentation_en-US" xlink:label="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan, Provision for Matching and Profit Sharing Contributions </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions" xlink:href="dco-20211231.xsd#dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions" xlink:to="lab_dco_DefinedContributionPlanProvisionforMatchingandProfitSharingContributions" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanInterestCost_52cc3eee-7d34-4768-9e82-c8e1596fcacc_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanInterestCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest cost </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanInterestCost_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanInterestCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Interest Cost </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanInterestCost" xlink:to="lab_us-gaap_DefinedBenefitPlanInterestCost" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeStatementLocationAxis_8a14dfd3-e9c8-44a7-972a-aba1e74afd2a_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Axis] </link:label>
<link:label id="lab_us-gaap_IncomeStatementLocationAxis_label_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Statement Location [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementLocationAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementLocationAxis" xlink:to="lab_us-gaap_IncomeStatementLocationAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_13c54a32-2bcb-4b84-b948-402f3ab23f07_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Amortization </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Accumulated Amortization </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="arc" order="1"/>
<link:label id="lab_srt_RangeMember_fc2c3494-bf42-4053-ad2b-22e667082416_terseLabel_en-US" xlink:label="lab_srt_RangeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Domain] </link:label>
<link:label id="lab_srt_RangeMember_label_en-US" xlink:label="lab_srt_RangeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statistical Measurement [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeMember" xlink:to="lab_srt_RangeMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_4b7b2e31-b549-43f0-a001-5bc1c3467a7b_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Future Long Term Debt Payments </link:label>
<link:label id="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Maturities of Long-term Debt [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityIncorporationStateCountryCode_018afe84-9f06-4656-97f5-e0bb9b0f2e12_terseLabel_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Incorporation, State or Country Code </link:label>
<link:label id="lab_dei_EntityIncorporationStateCountryCode_label_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Incorporation, State or Country Code </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityIncorporationStateCountryCode"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityIncorporationStateCountryCode" xlink:to="lab_dei_EntityIncorporationStateCountryCode" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AdditionalPaidInCapitalCommonStock_e4a323e7-5846-4808-a8b3-0a29b32d15a7_terseLabel_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapitalCommonStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional paid-in capital </link:label>
<link:label id="lab_us-gaap_AdditionalPaidInCapitalCommonStock_label_en-US" xlink:label="lab_us-gaap_AdditionalPaidInCapitalCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Additional Paid in Capital, Common Stock </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="lab_us-gaap_AdditionalPaidInCapitalCommonStock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RestructuringCostAndReserveAxis_fa3a0cf7-29a9-4301-8b5e-94eb0e0e9b0a_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCostAndReserveAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restructuring Type [Axis] </link:label>
<link:label id="lab_us-gaap_RestructuringCostAndReserveAxis_label_en-US" xlink:label="lab_us-gaap_RestructuringCostAndReserveAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restructuring Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis" xlink:to="lab_us-gaap_RestructuringCostAndReserveAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dco_RaytheonCompanyMember_97e42f75-af57-4cf4-9df1-188fced72d1e_terseLabel_en-US" xlink:label="lab_dco_RaytheonCompanyMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raytheon </link:label>
<link:label id="lab_dco_RaytheonCompanyMember_label_en-US" xlink:label="lab_dco_RaytheonCompanyMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raytheon Company [Member] </link:label>
<link:label id="lab_dco_RaytheonCompanyMember_documentation_en-US" xlink:label="lab_dco_RaytheonCompanyMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raytheon Company [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_RaytheonCompanyMember" xlink:href="dco-20211231.xsd#dco_RaytheonCompanyMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_RaytheonCompanyMember" xlink:to="lab_dco_RaytheonCompanyMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_TechnologyMember_ec83d3ab-72e7-4c98-9b97-d852732ef1de_terseLabel_en-US" xlink:label="lab_dco_TechnologyMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Technology </link:label>
<link:label id="lab_dco_TechnologyMember_label_en-US" xlink:label="lab_dco_TechnologyMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Technology [Member] </link:label>
<link:label id="lab_dco_TechnologyMember_documentation_en-US" xlink:label="lab_dco_TechnologyMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Technology [Member] </link:label>
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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_TechnologyMember" xlink:to="lab_dco_TechnologyMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherAssetsNoncurrent_336c1b3b-5528-48b3-b95f-a21f8daff405_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Assets </link:label>
<link:label id="lab_us-gaap_OtherAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Assets, Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetsNoncurrent" xlink:to="lab_us-gaap_OtherAssetsNoncurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_5ac3eff3-de72-4a58-beec-724ffd55ef6f_negatedLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected return on plan assets </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Return (Loss) on Plan Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:to="lab_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_966061e1-3ddb-4873-b085-1ab38039094b_terseLabel_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segments [Axis] </link:label>
<link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_label_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segments [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis" xlink:to="lab_us-gaap_StatementBusinessSegmentsAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward_7f93b6f6-0e60-43d0-9956-c05ccbc3c6de_terseLabel_en-US" xlink:label="lab_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized loss included in accumulated other comprehensive loss </link:label>
<link:label id="lab_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward_label_en-US" xlink:label="lab_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Roll Forward] </link:label>
<link:label id="lab_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward_documentation_en-US" xlink:label="lab_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward" xlink:href="dco-20211231.xsd#dco_PensionandOtherPostretirementBenefitPlansAccumulatedOtherComprehensiveIncomeLossbeforeTaxRollForward"/>
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<link:label id="lab_us-gaap_CompensationAndRetirementDisclosureAbstract_4ea063fc-4ed5-4349-91ca-b0b13d9ac4ad_terseLabel_en-US" xlink:label="lab_us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Benefits [Abstract] </link:label>
<link:label id="lab_us-gaap_CompensationAndRetirementDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Benefits [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CompensationAndRetirementDisclosureAbstract"/>
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<link:label id="lab_dei_EntityFileNumber_c9306c3b-0dc4-4bce-a16a-10a1c93dcdd7_terseLabel_en-US" xlink:label="lab_dei_EntityFileNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity File Number </link:label>
<link:label id="lab_dei_EntityFileNumber_label_en-US" xlink:label="lab_dei_EntityFileNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity File Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityFileNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFileNumber" xlink:to="lab_dei_EntityFileNumber" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_33d91921-7cd3-42f4-bc7a-c5693c7dc1fc_terseLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock-based compensation </link:label>
<link:label id="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_label_en-US" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> APIC, Share-based Payment Arrangement, Increase for Cost Recognition </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:to="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_2fc66543-2da2-44fe-81f9-622e9259d59a_negatedLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Forfeited (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired_aac411d9-9eb6-4279-bd11-64d5f195ac19_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for acquisition of Magnetic Seal LLC, net of cash acquired </link:label>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to Acquire Business Two, Net of Cash Acquired </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired" xlink:to="lab_us-gaap_PaymentsToAcquireBusinessTwoNetOfCashAcquired" xlink:type="arc" order="1"/>
<link:label id="lab_srt_ValuationAndQualifyingAccountsDisclosureLineItems_0c0dd3b0-48e2-4009-ae47-1c77cca6ee73_terseLabel_en-US" xlink:label="lab_srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] </link:label>
<link:label id="lab_srt_ValuationAndQualifyingAccountsDisclosureLineItems_label_en-US" xlink:label="lab_srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:to="lab_srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RetirementPlanNameDomain_64633d91-be45-4b0a-93ba-00c0b8d5d3d1_terseLabel_en-US" xlink:label="lab_us-gaap_RetirementPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Name [Domain] </link:label>
<link:label id="lab_us-gaap_RetirementPlanNameDomain_label_en-US" xlink:label="lab_us-gaap_RetirementPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Name [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanNameDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetirementPlanNameDomain" xlink:to="lab_us-gaap_RetirementPlanNameDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_aae6af9c-cd79-4d96-a248-14e78449479e_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Revenue by Major Customers, by Reporting Segments [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Revenue by Major Customers, by Reporting Segments [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
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<link:label id="lab_us-gaap_LongTermDebtAndCapitalLeaseObligations_f612ccfc-625e-4c90-afb0-a3b5cf240d92_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Less Current Portion </link:label>
<link:label id="lab_us-gaap_LongTermDebtAndCapitalLeaseObligations_label_en-US" xlink:label="lab_us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt and Lease Obligation </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:to="lab_us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_6a95d25c-7bb5-4022-b46c-8f0f3874fcb1_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair value of awards vested in period </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_dd318c56-b1e8-47b7-965a-3c821a48a5ac_verboseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average grant date fair value (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_8881cc7a-ff1b-4ece-8f47-3a2a2b85ec95_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Granted (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
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<link:label id="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_8bfe21b2-a424-4940-aca1-654944b88687_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitment fee </link:label>
<link:label id="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Commitment Fee Percentage </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:to="lab_us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_a6693bde-27d9-47a0-b415-99749bb78982_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Return on assets </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:to="lab_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:type="arc" order="1"/>
<link:label id="lab_srt_TitleOfIndividualWithRelationshipToEntityDomain_d6fe091f-796a-4445-b35a-43dc987f5e70_terseLabel_en-US" xlink:label="lab_srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of Individual [Domain] </link:label>
<link:label id="lab_srt_TitleOfIndividualWithRelationshipToEntityDomain_label_en-US" xlink:label="lab_srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Title of Individual [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="lab_srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther_8bd96c38-cecd-4e05-8f14-3ee765403c87_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred income tax deduction related to payroll taxes </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Other </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther" xlink:to="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_284f3e2f-2aa0-479e-be52-a8cbf32b8fca_terseLabel_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-current liabilities </link:label>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liability, Defined Benefit Plan, Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:to="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CreditFacilityDomain_8abfbbb4-59a4-41aa-94a9-df64f5e84691_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Domain] </link:label>
<link:label id="lab_us-gaap_CreditFacilityDomain_label_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facility [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CreditFacilityDomain" xlink:to="lab_us-gaap_CreditFacilityDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AssetsAbstract_5d19ebf7-ceaf-4a90-ae25-f69e0a1927ed_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets </link:label>
<link:label id="lab_us-gaap_AssetsAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="lab_us-gaap_AssetsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_1d447ece-046c-4d4e-836d-bd12a513550d_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2024 </link:label>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Three </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_cc7f8e14-b921-41b1-83a2-a8bc174cd407_negatedLabel_en-US" xlink:label="lab_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated goodwill impairment </link:label>
<link:label id="lab_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_label_en-US" xlink:label="lab_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill, Impaired, Accumulated Impairment Loss </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:to="lab_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LandMember_a3fa11c8-0dcc-4b08-a08c-56458078ee4e_terseLabel_en-US" xlink:label="lab_us-gaap_LandMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land </link:label>
<link:label id="lab_us-gaap_LandMember_label_en-US" xlink:label="lab_us-gaap_LandMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Land [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LandMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LandMember" xlink:to="lab_us-gaap_LandMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_3f27047a-9eee-47c6-ac5b-aeff0d97a093_terseLabel_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance leases </link:label>
<link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_label_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right-of-Use Asset Obtained in Exchange for Finance Lease Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:to="lab_us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SaleLeasebackTransactionLeaseContractTerms_68c62ae3-1364-40df-9421-96ad2a8dc255_terseLabel_en-US" xlink:label="lab_dco_SaleLeasebackTransactionLeaseContractTerms" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease contract terms </link:label>
<link:label id="lab_dco_SaleLeasebackTransactionLeaseContractTerms_label_en-US" xlink:label="lab_dco_SaleLeasebackTransactionLeaseContractTerms" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Lease Contract Terms </link:label>
<link:label id="lab_dco_SaleLeasebackTransactionLeaseContractTerms_documentation_en-US" xlink:label="lab_dco_SaleLeasebackTransactionLeaseContractTerms" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Lease Contract Terms </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SaleLeasebackTransactionLeaseContractTerms" xlink:href="dco-20211231.xsd#dco_SaleLeasebackTransactionLeaseContractTerms"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SaleLeasebackTransactionLeaseContractTerms" xlink:to="lab_dco_SaleLeasebackTransactionLeaseContractTerms" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_6d7ca7a5-12aa-4d3a-9c5f-b3914c463860_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Granted (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_10db41fd-43a0-4329-a228-794f72232ca5_verboseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Granted (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
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<link:label id="lab_us-gaap_ConcentrationRiskPercentage1_356520ba-9ea8-4d6e-b21b-76edbd5c6087_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskPercentage1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration percentage </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskPercentage1_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskPercentage1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk, Percentage </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskPercentage1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskPercentage1" xlink:to="lab_us-gaap_ConcentrationRiskPercentage1" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_9cdacf4a-f9d8-4934-a2f3-fe4faae5cccb_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill and Other Intangible Assets </link:label>
<link:label id="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill and Intangible Assets Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:to="lab_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_b7710cfe-5cf8-469f-a205-df5d0df2fde1_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property and Equipment and Depreciation </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_38716db4-a919-4d72-8def-9e1510507d25_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning balance (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_8040c330-351a-4571-afad-d784336a8ddf_periodEndLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending balance (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_a04ef6b8-7167-4f9b-a9a6-35c9e911f07c_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Discount rate </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:to="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_TradeNamesMember_7cb74b54-fb0b-413f-94c0-5ad7b928778b_terseLabel_en-US" xlink:label="lab_us-gaap_TradeNamesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trade name </link:label>
<link:label id="lab_us-gaap_TradeNamesMember_label_en-US" xlink:label="lab_us-gaap_TradeNamesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trade Names [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TradeNamesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TradeNamesMember" xlink:to="lab_us-gaap_TradeNamesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentAxis_6aa5e103-76af-44ab-9986-f879f71b4169_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Axis] </link:label>
<link:label id="lab_us-gaap_DebtInstrumentAxis_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentAxis" xlink:to="lab_us-gaap_DebtInstrumentAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_1b7a8780-4474-4b98-99ba-dc2f2ed7a5c2_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease not yet commenced, term of contract </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:to="lab_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_903efdc6-4bcc-4fe4-844f-eb72daa0b38c_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies </link:label>
<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent_2c67c383-f3bd-4ca1-8189-d4e16af6f0cb_terseLabel_en-US" xlink:label="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Changes in deferred tax assets </link:label>
<link:label id="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent_label_en-US" xlink:label="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets, Percent </link:label>
<link:label id="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent_documentation_en-US" xlink:label="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent" xlink:href="dco-20211231.xsd#dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent" xlink:to="lab_dco_EffectiveIncomeTaxRateReconciliationChangeinDeferredTaxAssetsPercent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SecuredDebtMember_44217272-81c7-4131-b65c-3b0fe40469dc_terseLabel_en-US" xlink:label="lab_us-gaap_SecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Debt </link:label>
<link:label id="lab_us-gaap_SecuredDebtMember_label_en-US" xlink:label="lab_us-gaap_SecuredDebtMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Secured Debt [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SecuredDebtMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SecuredDebtMember" xlink:to="lab_us-gaap_SecuredDebtMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_5392e0f7-8988-4831-b85f-c69b1653cd0e_terseLabel_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating leases </link:label>
<link:label id="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right-of-Use Asset Obtained in Exchange for Operating Lease Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:to="lab_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_631a9202-bb44-4b26-8f25-9484532a5774_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_15a63097-5c98-4266-a741-d0762a46371f_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Deferred Tax Assets (Liabilities) </link:label>
<link:label id="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Deferred Tax Assets and Liabilities [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_c08264ef-3381-4c0a-8a6d-f771636030ab_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vesting percentage </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LeaseWeightedAverageDiscountRateAbstract_89f3d25a-4bce-42a9-aa4f-a14e064348aa_terseLabel_en-US" xlink:label="lab_dco_LeaseWeightedAverageDiscountRateAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Discount Rate </link:label>
<link:label id="lab_dco_LeaseWeightedAverageDiscountRateAbstract_label_en-US" xlink:label="lab_dco_LeaseWeightedAverageDiscountRateAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Weighted Average Discount Rate [Abstract] </link:label>
<link:label id="lab_dco_LeaseWeightedAverageDiscountRateAbstract_documentation_en-US" xlink:label="lab_dco_LeaseWeightedAverageDiscountRateAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease, Weighted Average Discount Rate [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LeaseWeightedAverageDiscountRateAbstract" xlink:href="dco-20211231.xsd#dco_LeaseWeightedAverageDiscountRateAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LeaseWeightedAverageDiscountRateAbstract" xlink:to="lab_dco_LeaseWeightedAverageDiscountRateAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_TopTenCustomersMember_8e0c4bb7-759d-4985-ac3a-7fa15f9e81c9_terseLabel_en-US" xlink:label="lab_dco_TopTenCustomersMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Top ten customers </link:label>
<link:label id="lab_dco_TopTenCustomersMember_label_en-US" xlink:label="lab_dco_TopTenCustomersMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Top Ten Customers [Member] </link:label>
<link:label id="lab_dco_TopTenCustomersMember_documentation_en-US" xlink:label="lab_dco_TopTenCustomersMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Top Ten Customers [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_TopTenCustomersMember" xlink:href="dco-20211231.xsd#dco_TopTenCustomersMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_TopTenCustomersMember" xlink:to="lab_dco_TopTenCustomersMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_50677a65-208e-4bc1-8dfd-6bde79d9bc50_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies Disclosure [Abstract] </link:label>
<link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="lab_us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_169f0d8c-0373-4738-87f0-c3f4b88392f2_terseLabel_en-US" xlink:label="lab_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revision of Prior Period, Reclassification, Adjustment </link:label>
<link:label id="lab_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_label_en-US" xlink:label="lab_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revision of Prior Period, Reclassification, Adjustment [Member] </link:label>
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<link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_6f15612f-43ee-451b-b6d4-793c9a307b6c_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset allocation percentage </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Target Allocation, Percentage </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
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<link:label id="lab_us-gaap_DerivativeAverageFixedInterestRate_7e0ba74f-5e0b-47fe-ad7c-6644794bfcea_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAverageFixedInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Average fixed interest rate </link:label>
<link:label id="lab_us-gaap_DerivativeAverageFixedInterestRate_label_en-US" xlink:label="lab_us-gaap_DerivativeAverageFixedInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative, Average Fixed Interest Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAverageFixedInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAverageFixedInterestRate"/>
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<link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6c5ed8de-239a-48cb-858b-6674b90a67f0_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Segment Reporting Information, by Segment [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Segment Reporting Information, by Segment [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
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<link:label id="lab_us-gaap_TaxCreditCarryforwardTable_e7ae864f-5db7-4fad-b7c3-93fdceaccc8c_terseLabel_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax Credit Carryforward [Table] </link:label>
<link:label id="lab_us-gaap_TaxCreditCarryforwardTable_label_en-US" xlink:label="lab_us-gaap_TaxCreditCarryforwardTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax Credit Carryforward [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxCreditCarryforwardTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TaxCreditCarryforwardTable" xlink:to="lab_us-gaap_TaxCreditCarryforwardTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_a66c25d8-ba42-4fee-866f-f46a7a8b7350_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining borrowing capacity </link:label>
<link:label id="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Remaining Borrowing Capacity </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:to="lab_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_e0103c22-dbe3-484f-ad5d-04a75a7a9380_terseLabel_en-US" xlink:label="lab_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived Intangible Assets, Major Class Name [Domain] </link:label>
<link:label id="lab_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_label_en-US" xlink:label="lab_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived Intangible Assets, Major Class Name [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="lab_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_b2c42779-8bbd-4517-827b-c5a8ec10db93_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Three </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_8132ce7a-bae7-4e0a-96d8-643584493ae4_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, after Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive"/>
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<link:label id="lab_us-gaap_AllowanceForCreditLossMember_07065492-9c69-4aad-bd4a-d0e909f8dca7_terseLabel_en-US" xlink:label="lab_us-gaap_AllowanceForCreditLossMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Allowance for Credit Losses, Doubtful Accounts </link:label>
<link:label id="lab_us-gaap_AllowanceForCreditLossMember_label_en-US" xlink:label="lab_us-gaap_AllowanceForCreditLossMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Allowance, Credit Loss [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForCreditLossMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllowanceForCreditLossMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AllowanceForCreditLossMember" xlink:to="lab_us-gaap_AllowanceForCreditLossMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesTypeAxis_7283b072-a73e-48fd-b866-3393f2db11b4_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesTypeAxis_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
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<link:label id="lab_us-gaap_DisaggregationOfRevenueTableTextBlock_4a0591d2-cc89-4cce-ae28-4a93f3b0b0aa_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Disaggregation of Revenue </link:label>
<link:label id="lab_us-gaap_DisaggregationOfRevenueTableTextBlock_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disaggregation of Revenue [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisaggregationOfRevenueTableTextBlock"/>
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<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_0f49974f-edf5-4404-bd58-76d8a22ce2e0_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:type="arc" order="1"/>
<link:label id="lab_dco_BoeingMember_068f9914-52fe-4b45-94ca-35bc5d9196c8_terseLabel_en-US" xlink:label="lab_dco_BoeingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Boeing </link:label>
<link:label id="lab_dco_BoeingMember_label_en-US" xlink:label="lab_dco_BoeingMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Boeing [Member] </link:label>
<link:label id="lab_dco_BoeingMember_documentation_en-US" xlink:label="lab_dco_BoeingMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Boeing [Member] </link:label>
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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_BoeingMember" xlink:to="lab_dco_BoeingMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_905ce091-7233-4294-99f7-fab541ca7cc0_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Outstanding </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
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<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_900dd3f5-1c68-4cdb-9c89-1a687e145f2f_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-lived intangibles </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock_d5660086-8785-414e-a7be-4e697fdc630f_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Nonvested Options Activity </link:label>
<link:label id="lab_us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Nonvested Share Activity [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_046270e0-7456-4971-bc6c-7ca7be506c22_verboseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax credit carryforwards </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_814369b4-abb9-4af3-b338-e47a2dbc8f4a_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Federal tax credit carryforwards </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Tax Credit Carryforwards </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards"/>
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<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_2166a53f-ac87-47df-923c-af0bcf9f64df_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted- Average Grant Date Fair Value </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValueAbstract"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_0252d3e6-90d2-4f45-9c2c-179a8df659a6_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of shares authorized (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
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<link:label id="lab_us-gaap_OperatingLeasePayments_38214922-56e0-428b-aaec-9488323838ec_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeasePayments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating cash flows from operating leases </link:label>
<link:label id="lab_us-gaap_OperatingLeasePayments_label_en-US" xlink:label="lab_us-gaap_OperatingLeasePayments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Payments </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasePayments" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasePayments"/>
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<link:label id="lab_us-gaap_BusinessCombinationConsiderationTransferred1_4d2c20a7-f461-4cb6-8f1e-d2e4eb593730_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consideration transferred </link:label>
<link:label id="lab_us-gaap_BusinessCombinationConsiderationTransferred1_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Consideration Transferred </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
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<link:label id="lab_us-gaap_ProvisionForDoubtfulAccounts_a8fe604b-aff6-4caf-9eb9-c78040863d04_terseLabel_en-US" xlink:label="lab_us-gaap_ProvisionForDoubtfulAccounts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> (Recovery of) provision for credit losses </link:label>
<link:label id="lab_us-gaap_ProvisionForDoubtfulAccounts_label_en-US" xlink:label="lab_us-gaap_ProvisionForDoubtfulAccounts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable, Credit Loss Expense (Reversal) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
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<link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_25d581b0-c23b-4927-a916-e9a38703304c_totalLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term debt, gross </link:label>
<link:label id="lab_us-gaap_DebtInstrumentCarryingAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentCarryingAmount" xlink:to="lab_us-gaap_DebtInstrumentCarryingAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GoodwillRollForward_1680bd01-a331-41b0-8c2c-0a134cb389a1_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill [Roll Forward] </link:label>
<link:label id="lab_us-gaap_GoodwillRollForward_label_en-US" xlink:label="lab_us-gaap_GoodwillRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillRollForward"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillRollForward" xlink:to="lab_us-gaap_GoodwillRollForward" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_5b33758e-c902-411c-b82d-e4ce64231dfa_terseLabel_en-US" xlink:label="lab_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] </link:label>
<link:label id="lab_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_label_en-US" xlink:label="lab_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward"/>
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<link:label id="lab_dco_DefinedContributionPlansParticipantGroupOneMember_265d3ef0-b503-42c0-8c39-1ae0dc63b35f_terseLabel_en-US" xlink:label="lab_dco_DefinedContributionPlansParticipantGroupOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Plan One covering all employees, other than employees of Miltec </link:label>
<link:label id="lab_dco_DefinedContributionPlansParticipantGroupOneMember_label_en-US" xlink:label="lab_dco_DefinedContributionPlansParticipantGroupOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plans Participant Group One [Member] </link:label>
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<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedContributionPlansParticipantGroupOneMember" xlink:href="dco-20211231.xsd#dco_DefinedContributionPlansParticipantGroupOneMember"/>
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<link:label id="lab_us-gaap_ProceedsFromPreviousAcquisition_02bde20b-25ab-443f-b2e5-411a7b9f849c_verboseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromPreviousAcquisition" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Post closing cash received from the acquisition of Nobles Worldwide, Inc., net </link:label>
<link:label id="lab_us-gaap_ProceedsFromPreviousAcquisition_label_en-US" xlink:label="lab_us-gaap_ProceedsFromPreviousAcquisition" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Previous Acquisition </link:label>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther_1cd29a69-5893-4aa9-a47c-dc0e534b80ba_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other tax credits </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent </link:label>
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<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_fbccd1b8-1255-4d93-bfb8-1c957a565215_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Liabilities and Shareholders’ Equity </link:label>
<link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities and Equity </link:label>
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<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_d448a3e7-8c97-4593-ab92-b4e1f6549e7b_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Other Adjustments, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments"/>
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<link:label id="lab_us-gaap_OtherAccruedLiabilitiesCurrent_fd65e5bf-896e-4b2d-b359-dea729901614_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other </link:label>
<link:label id="lab_us-gaap_OtherAccruedLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_OtherAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Accrued Liabilities, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent"/>
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<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_1fd58856-368b-45d0-8e0a-f68f1ca41aff_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Change in net unrealized (losses) gains on cash flow hedges, net of tax of $391, $57, and $29 for 2021, 2020, and 2019, respectively </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_9a019e3f-0d2b-4139-9f1f-3bd99538527a_verboseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash flow hedge, gain (loss) </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SaleLeasebackTransactionLeaseRenewOption_b4bd45be-e8b9-47c8-9b6a-29b67948602c_terseLabel_en-US" xlink:label="lab_dco_SaleLeasebackTransactionLeaseRenewOption" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease renew option </link:label>
<link:label id="lab_dco_SaleLeasebackTransactionLeaseRenewOption_label_en-US" xlink:label="lab_dco_SaleLeasebackTransactionLeaseRenewOption" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Lease Renew Option </link:label>
<link:label id="lab_dco_SaleLeasebackTransactionLeaseRenewOption_documentation_en-US" xlink:label="lab_dco_SaleLeasebackTransactionLeaseRenewOption" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Lease Renew Option </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SaleLeasebackTransactionLeaseRenewOption" xlink:href="dco-20211231.xsd#dco_SaleLeasebackTransactionLeaseRenewOption"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SaleLeasebackTransactionLeaseRenewOption" xlink:to="lab_dco_SaleLeasebackTransactionLeaseRenewOption" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember_299df1cb-5169-4185-b99a-5bcf6b754175_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> First Anniversary </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Tranche One [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:to="lab_us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_80c70bf4-9bb7-4eda-834e-25174cb1989e_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract liabilities </link:label>
<link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract with Customer, Liability, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_1b3eaf02-f966-4a93-ae15-dd9db965d811_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SignificantAccountingPoliciesTable_c2644017-0ad1-4101-b1c3-dc39923d155b_terseLabel_en-US" xlink:label="lab_dco_SignificantAccountingPoliciesTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Table] </link:label>
<link:label id="lab_dco_SignificantAccountingPoliciesTable_label_en-US" xlink:label="lab_dco_SignificantAccountingPoliciesTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Table] </link:label>
<link:label id="lab_dco_SignificantAccountingPoliciesTable_documentation_en-US" xlink:label="lab_dco_SignificantAccountingPoliciesTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SignificantAccountingPoliciesTable" xlink:href="dco-20211231.xsd#dco_SignificantAccountingPoliciesTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SignificantAccountingPoliciesTable" xlink:to="lab_dco_SignificantAccountingPoliciesTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_2d221e24-67bc-43d3-b94d-8134399f735f_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Exercised (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_7b08edb3-58ed-40a7-a9f2-e49e68dc2ee5_negatedLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Benefits paid </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Benefits Paid </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:to="lab_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeLeaseDescriptionTable_86f0bc51-0c07-42a0-a1d6-e0ea703938cf_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeLeaseDescriptionTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Description [Table] </link:label>
<link:label id="lab_us-gaap_LesseeLeaseDescriptionTable_label_en-US" xlink:label="lab_us-gaap_LesseeLeaseDescriptionTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Description [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable" xlink:to="lab_us-gaap_LesseeLeaseDescriptionTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ConcentrationRiskLineItems_8256fb36-baa0-47e7-8539-7b6c528b85ec_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk [Line Items] </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskLineItems_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="lab_us-gaap_ConcentrationRiskLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_50012ca8-bd5f-4f09-8992-54b1db84d790_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment, Year Two </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:to="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:type="arc" order="1"/>
<link:label id="lab_srt_MinimumMember_3c9c3348-6f01-482a-b626-a822db3edb25_terseLabel_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum </link:label>
<link:label id="lab_srt_MinimumMember_label_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Minimum [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MinimumMember" xlink:to="lab_srt_MinimumMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount_6fb3f6fc-8246-483c-96c5-d78652f1a8cd_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension plan assets </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount" xlink:to="lab_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GrossProfit_9b4dac13-1524-4fe0-9fa2-b82c0f999506_totalLabel_en-US" xlink:label="lab_us-gaap_GrossProfit" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gross Profit </link:label>
<link:label id="lab_us-gaap_GrossProfit_label_en-US" xlink:label="lab_us-gaap_GrossProfit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gross Profit </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GrossProfit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GrossProfit" xlink:to="lab_us-gaap_GrossProfit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_4ca7b408-4b2d-492f-9f35-0832194f2da6_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2022 </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, Year Two </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="arc" order="1"/>
<link:label id="lab_dco_RightOfUseAssetAmortization_36c14757-f937-4244-b06d-a423b8002581_terseLabel_en-US" xlink:label="lab_dco_RightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-cash operating lease cost </link:label>
<link:label id="lab_dco_RightOfUseAssetAmortization_label_en-US" xlink:label="lab_dco_RightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right Of Use Asset Amortization </link:label>
<link:label id="lab_dco_RightOfUseAssetAmortization_documentation_en-US" xlink:label="lab_dco_RightOfUseAssetAmortization" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right Of Use Asset Amortization </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_RightOfUseAssetAmortization" xlink:href="dco-20211231.xsd#dco_RightOfUseAssetAmortization"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_RightOfUseAssetAmortization" xlink:to="lab_dco_RightOfUseAssetAmortization" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpense_865c1014-2bab-4103-90e6-72f2c0817a8a_terseLabel_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling, General and Administrative Expenses </link:label>
<link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpense_label_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Selling, General and Administrative Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="lab_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredFinanceCostsNet_00d2342c-c16e-49ab-a6f7-33ea55d1d00c_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less debt issuance costs </link:label>
<link:label id="lab_us-gaap_DeferredFinanceCostsNet_label_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Issuance Costs, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredFinanceCostsNet" xlink:to="lab_us-gaap_DeferredFinanceCostsNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_8e295954-45fc-4a5b-9d63-021db8bb852b_terseLabel_en-US" xlink:label="lab_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived Intangible Assets [Axis] </link:label>
<link:label id="lab_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_label_en-US" xlink:label="lab_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived Intangible Assets [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
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<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_e355e43f-5a01-4919-9357-6a5da4dfa068_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] </link:label>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
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<link:label id="lab_us-gaap_PreferredStockSharesAuthorized_b258910c-e037-467f-b53e-e5f1234b2f71_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, shares authorized (in shares) </link:label>
<link:label id="lab_us-gaap_PreferredStockSharesAuthorized_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Shares Authorized </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
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<link:label id="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription_e24a4b5b-162f-4178-80b8-c9cb86a4d5e7_terseLabel_en-US" xlink:label="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reclassifications </link:label>
<link:label id="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription_label_en-US" xlink:label="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reclassification, Comparability Adjustment [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromSaleOfProductiveAssets_d6959408-6339-470d-809c-43383e0c3d4a_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from sale of assets </link:label>
<link:label id="lab_us-gaap_ProceedsFromSaleOfProductiveAssets_label_en-US" xlink:label="lab_us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Sale of Productive Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:to="lab_us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:type="arc" order="1"/>
<link:label id="lab_srt_CumulativeEffectPeriodOfAdoptionAxis_9cf8d126-b3cb-4c78-8595-42a126622a92_terseLabel_en-US" xlink:label="lab_srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumulative Effect, Period of Adoption [Axis] </link:label>
<link:label id="lab_srt_CumulativeEffectPeriodOfAdoptionAxis_label_en-US" xlink:label="lab_srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumulative Effect, Period of Adoption [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:to="lab_srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_496c1c18-f33e-4384-8364-bc07128da96b_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Insurance recoveries related to property and equipment </link:label>
<link:label id="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Insurance Settlement, Investing Activities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromInsuranceSettlementInvestingActivities"/>
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<link:label id="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_7e86cc16-dbf5-4cc1-9515-1e579f62e697_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of outstanding common stock acquired </link:label>
<link:label id="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition, Percentage of Voting Interests Acquired </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:to="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_39412b9c-3114-4ca1-8156-bda30e1c6f3f_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>
<link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Term Debt, Maturity, Year Four </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_4af5c03b-152c-4622-b412-87abc6ff90c9_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Purchase price of acquisition </link:label>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to Acquire Businesses, Net of Cash Acquired </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="lab_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_84b47a57-c534-4aed-b90e-21d6cd39432f_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amounts recognized in the consolidated balance sheet </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:to="lab_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_0717c5a0-2054-4dfa-8889-da456c481a29_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Provision for Income Tax Expense (Benefit) </link:label>
<link:label id="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate_aa685ca9-e30b-4405-b308-ed3ab5591da2_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Discount from market price, offering date </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LineOfCreditMember_5f044954-37b5-4f57-be82-41ecc868c30d_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revolving credit facility </link:label>
<link:label id="lab_us-gaap_LineOfCreditMember_label_en-US" xlink:label="lab_us-gaap_LineOfCreditMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditMember" xlink:to="lab_us-gaap_LineOfCreditMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_4632ced3-c5b1-4b71-8794-77b91d148797_terseLabel_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock-Based Compensation </link:label>
<link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_label_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueInputsLevel3Member_e8227862-dd48-4fd7-b60d-5296ca8e97d5_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Level 3 </link:label>
<link:label id="lab_us-gaap_FairValueInputsLevel3Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fair Value, Inputs, Level 3 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel3Member" xlink:to="lab_us-gaap_FairValueInputsLevel3Member" xlink:type="arc" order="1"/>
<link:label id="lab_dco_PercentageOfRevenuesFromContractWithCustomers_d4569557-d72f-4559-ac0e-8841981c2b7a_terseLabel_en-US" xlink:label="lab_dco_PercentageOfRevenuesFromContractWithCustomers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage of revenues </link:label>
<link:label id="lab_dco_PercentageOfRevenuesFromContractWithCustomers_label_en-US" xlink:label="lab_dco_PercentageOfRevenuesFromContractWithCustomers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Revenues From Contract With Customers </link:label>
<link:label id="lab_dco_PercentageOfRevenuesFromContractWithCustomers_documentation_en-US" xlink:label="lab_dco_PercentageOfRevenuesFromContractWithCustomers" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Percentage Of Revenues From Contract With Customers </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_PercentageOfRevenuesFromContractWithCustomers" xlink:href="dco-20211231.xsd#dco_PercentageOfRevenuesFromContractWithCustomers"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_PercentageOfRevenuesFromContractWithCustomers" xlink:to="lab_dco_PercentageOfRevenuesFromContractWithCustomers" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NumberOfReportableSegments_1b8422bf-590a-42a7-811b-6a46ba9b3d03_terseLabel_en-US" xlink:label="lab_us-gaap_NumberOfReportableSegments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of reportable segments </link:label>
<link:label id="lab_us-gaap_NumberOfReportableSegments_label_en-US" xlink:label="lab_us-gaap_NumberOfReportableSegments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of Reportable Segments </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfReportableSegments"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NumberOfReportableSegments" xlink:to="lab_us-gaap_NumberOfReportableSegments" xlink:type="arc" order="1"/>
<link:label id="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member_e7a7caa9-7a8d-40da-bf38-793aed143e4b_terseLabel_en-US" xlink:label="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2019 Revolving Credit Facility </link:label>
<link:label id="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member_label_en-US" xlink:label="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Revolving Credit Facility Due December 20, 2024 [Member] </link:label>
<link:label id="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member_documentation_en-US" xlink:label="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Revolving Credit Facility Due December 20, 2024 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_NewRevolvingCreditFacilityDueDecember202024Member" xlink:href="dco-20211231.xsd#dco_NewRevolvingCreditFacilityDueDecember202024Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_NewRevolvingCreditFacilityDueDecember202024Member" xlink:to="lab_dco_NewRevolvingCreditFacilityDueDecember202024Member" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LettersOfCreditOutstandingAmount_6610b92e-a22d-4365-812e-4de83c759957_terseLabel_en-US" xlink:label="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Outstanding standby letters of credit </link:label>
<link:label id="lab_us-gaap_LettersOfCreditOutstandingAmount_label_en-US" xlink:label="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Letters of Credit Outstanding, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LettersOfCreditOutstandingAmount" xlink:to="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DisaggregationOfRevenueLineItems_9548ca1d-2886-424f-89e9-ab741bd75dbb_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disaggregation of Revenue [Line Items] </link:label>
<link:label id="lab_us-gaap_DisaggregationOfRevenueLineItems_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disaggregation of Revenue [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems" xlink:to="lab_us-gaap_DisaggregationOfRevenueLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GoodwillAcquiredDuringPeriod_6f1dd3d0-c4a1-4ce9-b2a6-5b5ff11b71d6_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillAcquiredDuringPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill from acquisition during period </link:label>
<link:label id="lab_us-gaap_GoodwillAcquiredDuringPeriod_label_en-US" xlink:label="lab_us-gaap_GoodwillAcquiredDuringPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill, Acquired During Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GoodwillAcquiredDuringPeriod" xlink:to="lab_us-gaap_GoodwillAcquiredDuringPeriod" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_836eaa9e-949e-4ee8-99a3-f8b36c80e23c_terseLabel_en-US" xlink:label="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basis of Presentation </link:label>
<link:label id="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basis of Accounting, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:to="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_0767f6e5-bc9b-42b0-adba-4cfaaa8bd421_terseLabel_en-US" xlink:label="lab_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> LaBarge Retirement Plan </link:label>
<link:label id="lab_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_label_en-US" xlink:label="lab_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Postretirement Benefits Plan [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:to="lab_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PerformanceSharesMember_eb486f3c-ab0f-4793-bec7-f1bb397ff84e_terseLabel_en-US" xlink:label="lab_us-gaap_PerformanceSharesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Performance Stock Units </link:label>
<link:label id="lab_us-gaap_PerformanceSharesMember_label_en-US" xlink:label="lab_us-gaap_PerformanceSharesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Performance Shares [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PerformanceSharesMember" xlink:to="lab_us-gaap_PerformanceSharesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommitmentsAndContingencies_c579d1d6-dcb7-4b97-9982-ddd829adf29e_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies </link:label>
<link:label id="lab_us-gaap_CommitmentsAndContingencies_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingencies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Commitments and Contingencies </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingencies"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommitmentsAndContingencies" xlink:to="lab_us-gaap_CommitmentsAndContingencies" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LongTermDebtByMaturityAbstract_b0fd66e8-5537-432c-a303-2aa62a50903d_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtByMaturityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Fiscal Year Maturity [Abstract] </link:label>
<link:label id="lab_us-gaap_LongTermDebtByMaturityAbstract_label_en-US" xlink:label="lab_us-gaap_LongTermDebtByMaturityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Fiscal Year Maturity [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtByMaturityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtByMaturityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtByMaturityAbstract" xlink:to="lab_us-gaap_LongTermDebtByMaturityAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_d7f18152-7b6b-432d-932d-7cc57d21d77e_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated other comprehensive loss </link:label>
<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Other Comprehensive Income (Loss), Net of Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityEmergingGrowthCompany_ad5a2fcf-3e69-43d2-afbf-0c72d3671636_terseLabel_en-US" xlink:label="lab_dei_EntityEmergingGrowthCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Emerging Growth Company </link:label>
<link:label id="lab_dei_EntityEmergingGrowthCompany_label_en-US" xlink:label="lab_dei_EntityEmergingGrowthCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Emerging Growth Company </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityEmergingGrowthCompany"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityEmergingGrowthCompany" xlink:to="lab_dei_EntityEmergingGrowthCompany" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_14ded302-5eea-4310-afa6-d6afc2539503_terseLabel_en-US" xlink:label="lab_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts receivable, allowance for credit losses </link:label>
<link:label id="lab_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_label_en-US" xlink:label="lab_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Receivable, Allowance for Credit Loss, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:to="lab_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PaymentsOfDebtIssuanceCosts_86526a4a-fda3-45d5-931c-d6b7334f6600_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt issuance costs </link:label>
<link:label id="lab_us-gaap_PaymentsOfDebtIssuanceCosts_label_en-US" xlink:label="lab_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments of Debt Issuance Costs </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="lab_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:type="arc" order="1"/>
<link:label id="lab_dei_AuditorName_a23a95af-3269-4985-ad80-60d722e7aaa3_terseLabel_en-US" xlink:label="lab_dei_AuditorName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Name </link:label>
<link:label id="lab_dei_AuditorName_label_en-US" xlink:label="lab_dei_AuditorName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Name </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_AuditorName" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorName"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AuditorName" xlink:to="lab_dei_AuditorName" xlink:type="arc" order="1"/>
<link:label id="lab_dei_CoverAbstract_label_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cover [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_CoverAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CoverAbstract" xlink:to="lab_dei_CoverAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_GuaymasMexicoMember_26ed1c4b-c9b8-4c00-a158-9a67dd51faa8_terseLabel_en-US" xlink:label="lab_dco_GuaymasMexicoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Facility Fire In Guaymas, Mexico </link:label>
<link:label id="lab_dco_GuaymasMexicoMember_label_en-US" xlink:label="lab_dco_GuaymasMexicoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Guaymas, Mexico [Member] </link:label>
<link:label id="lab_dco_GuaymasMexicoMember_documentation_en-US" xlink:label="lab_dco_GuaymasMexicoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Guaymas, Mexico </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_GuaymasMexicoMember" xlink:href="dco-20211231.xsd#dco_GuaymasMexicoMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_GuaymasMexicoMember" xlink:to="lab_dco_GuaymasMexicoMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DeferredTaxAssetsLongTermContracts_9496ad86-3fbe-4056-8282-4a68443877da_terseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsLongTermContracts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract overrun reserves </link:label>
<link:label id="lab_dco_DeferredTaxAssetsLongTermContracts_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsLongTermContracts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Long Term Contracts </link:label>
<link:label id="lab_dco_DeferredTaxAssetsLongTermContracts_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsLongTermContracts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Long term Contracts </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxAssetsLongTermContracts" xlink:href="dco-20211231.xsd#dco_DeferredTaxAssetsLongTermContracts"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DeferredTaxAssetsLongTermContracts" xlink:to="lab_dco_DeferredTaxAssetsLongTermContracts" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtLongtermAndShorttermCombinedAmount_892c3298-e3a3-4180-a105-c1d8cf1216f0_totalLabel_en-US" xlink:label="lab_us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Debt </link:label>
<link:label id="lab_us-gaap_DebtLongtermAndShorttermCombinedAmount_label_en-US" xlink:label="lab_us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt, Long-term and Short-term, Combined Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:to="lab_us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_5ba20878-0097-4a29-88c1-774a05115339_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less imputed interest </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, Undiscounted Excess Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="lab_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="arc" order="1"/>
<link:label id="lab_dco_AuditInformationAbstract_label_en-US" xlink:label="lab_dco_AuditInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Audit Information [Abstract] </link:label>
<link:label id="lab_dco_AuditInformationAbstract_documentation_en-US" xlink:label="lab_dco_AuditInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Audit Information </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_AuditInformationAbstract" xlink:href="dco-20211231.xsd#dco_AuditInformationAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_AuditInformationAbstract" xlink:to="lab_dco_AuditInformationAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LesseeLeaseRenewalTerm_76804fa6-bbfd-4534-9528-e0a68c6372b8_terseLabel_en-US" xlink:label="lab_dco_LesseeLeaseRenewalTerm" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lease renewal term </link:label>
<link:label id="lab_dco_LesseeLeaseRenewalTerm_label_en-US" xlink:label="lab_dco_LesseeLeaseRenewalTerm" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Renewal Term </link:label>
<link:label id="lab_dco_LesseeLeaseRenewalTerm_documentation_en-US" xlink:label="lab_dco_LesseeLeaseRenewalTerm" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Lease, Renewal Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LesseeLeaseRenewalTerm" xlink:href="dco-20211231.xsd#dco_LesseeLeaseRenewalTerm"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LesseeLeaseRenewalTerm" xlink:to="lab_dco_LesseeLeaseRenewalTerm" xlink:type="arc" order="1"/>
<link:label id="lab_dco_IndustrialMember_ed91db6c-4c27-4eb2-a3f0-9170b87dc95e_terseLabel_en-US" xlink:label="lab_dco_IndustrialMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Industrial </link:label>
<link:label id="lab_dco_IndustrialMember_label_en-US" xlink:label="lab_dco_IndustrialMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Industrial [Member] </link:label>
<link:label id="lab_dco_IndustrialMember_documentation_en-US" xlink:label="lab_dco_IndustrialMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Industrial [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_IndustrialMember" xlink:href="dco-20211231.xsd#dco_IndustrialMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_IndustrialMember" xlink:to="lab_dco_IndustrialMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_AccruedIncomeTaxesAndOtherCurrent_0db03da7-6cf2-4366-8df0-8dcc8ffca258_terseLabel_en-US" xlink:label="lab_dco_AccruedIncomeTaxesAndOtherCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued income tax and sales tax </link:label>
<link:label id="lab_dco_AccruedIncomeTaxesAndOtherCurrent_label_en-US" xlink:label="lab_dco_AccruedIncomeTaxesAndOtherCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Income Taxes And Other Current </link:label>
<link:label id="lab_dco_AccruedIncomeTaxesAndOtherCurrent_documentation_en-US" xlink:label="lab_dco_AccruedIncomeTaxesAndOtherCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Income Taxes And Other, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_AccruedIncomeTaxesAndOtherCurrent" xlink:href="dco-20211231.xsd#dco_AccruedIncomeTaxesAndOtherCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_AccruedIncomeTaxesAndOtherCurrent" xlink:to="lab_dco_AccruedIncomeTaxesAndOtherCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities_42d5d1d4-6704-40fd-91d1-36d09e448be1_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Insurance recoveries related to loss on operating assets </link:label>
<link:label id="lab_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Insurance Settlement, Operating Activities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromInsuranceSettlementOperatingActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities" xlink:to="lab_us-gaap_ProceedsFromInsuranceSettlementOperatingActivities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EnvironmentalCostExpensePolicy_766e4771-8c48-4572-a70a-3ec820cd48e1_terseLabel_en-US" xlink:label="lab_us-gaap_EnvironmentalCostExpensePolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Environmental Liabilities </link:label>
<link:label id="lab_us-gaap_EnvironmentalCostExpensePolicy_label_en-US" xlink:label="lab_us-gaap_EnvironmentalCostExpensePolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Environmental Cost, Expense Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalCostExpensePolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EnvironmentalCostExpensePolicy"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EnvironmentalCostExpensePolicy" xlink:to="lab_us-gaap_EnvironmentalCostExpensePolicy" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_34f8a9ea-6e29-4dbe-b687-59bd10a868bf_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Less imputed interest </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, Undiscounted Excess Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:to="lab_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromLifeInsurancePolicies_60d100d8-9445-4ff9-b9e8-9d612fd85056_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromLifeInsurancePolicies" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Life insurance proceeds </link:label>
<link:label id="lab_us-gaap_ProceedsFromLifeInsurancePolicies_label_en-US" xlink:label="lab_us-gaap_ProceedsFromLifeInsurancePolicies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Life Insurance Policy </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLifeInsurancePolicies" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromLifeInsurancePolicies"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromLifeInsurancePolicies" xlink:to="lab_us-gaap_ProceedsFromLifeInsurancePolicies" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromSecuredLinesOfCredit_1e74062c-02bd-4472-8a96-c953e2025cb8_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromSecuredLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Borrowings from senior secured revolving credit facility </link:label>
<link:label id="lab_us-gaap_ProceedsFromSecuredLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_ProceedsFromSecuredLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Secured Lines of Credit </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSecuredLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSecuredLinesOfCredit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromSecuredLinesOfCredit" xlink:to="lab_us-gaap_ProceedsFromSecuredLinesOfCredit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_17842a4e-6900-4d80-9ac6-52226835ac82_terseLabel_en-US" xlink:label="lab_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current tax expense </link:label>
<link:label id="lab_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_label_en-US" xlink:label="lab_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Income Tax Expense (Benefit), Continuing Operations [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:to="lab_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend_9a80d7a2-e5e2-4fc9-a7cd-806014a48b43_terseLabel_en-US" xlink:label="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments due with option to extend </link:label>
<link:label id="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend_label_en-US" xlink:label="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, Payments, Due With Option To Extend </link:label>
<link:label id="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend_documentation_en-US" xlink:label="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, Payments, Due With Option To Extend </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend" xlink:href="dco-20211231.xsd#dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend" xlink:to="lab_dco_LesseeOperatingLeaseLiabilityPaymentsDueWithOptionToExtend" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_d0d154a1-5bad-410f-ac33-d35645a809c9_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2025 </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, to be Paid, Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommonStockMember_ae9538b8-c591-4533-a4d5-1c03c636595c_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock </link:label>
<link:label id="lab_us-gaap_CommonStockMember_label_en-US" xlink:label="lab_us-gaap_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockMember" xlink:to="lab_us-gaap_CommonStockMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock_d2a16d2d-1ebc-4e94-ac8f-fdc45c698d17_terseLabel_en-US" xlink:label="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Litigation and Commitments </link:label>
<link:label id="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock_label_en-US" xlink:label="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Litigation And Contingencies Policy [Policy Text Block] </link:label>
<link:label id="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock_documentation_en-US" xlink:label="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Litigation and Contingencies, Policy [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LitigationAndContingenciesPolicyPolicyTextBlock" xlink:href="dco-20211231.xsd#dco_LitigationAndContingenciesPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LitigationAndContingenciesPolicyPolicyTextBlock" xlink:to="lab_dco_LitigationAndContingenciesPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanFairValueofPooledFunds_01a649dc-e9fe-44d9-91a4-0bb1a6aa5aa0_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanFairValueofPooledFunds" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pooled funds </link:label>
<link:label id="lab_dco_DefinedBenefitPlanFairValueofPooledFunds_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanFairValueofPooledFunds" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Fair Value of Pooled Funds </link:label>
<link:label id="lab_dco_DefinedBenefitPlanFairValueofPooledFunds_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanFairValueofPooledFunds" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Fair Value of Pooled Funds </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanFairValueofPooledFunds" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanFairValueofPooledFunds"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanFairValueofPooledFunds" xlink:to="lab_dco_DefinedBenefitPlanFairValueofPooledFunds" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingIncomeLoss_f8ccc0a6-8f7c-46ee-869e-28ec2bab53e4_totalLabel_en-US" xlink:label="lab_us-gaap_OperatingIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Income </link:label>
<link:label id="lab_us-gaap_OperatingIncomeLoss_de2da3bd-a9c4-40ac-b83c-0b7e973085b4_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Income (Loss) </link:label>
<link:label id="lab_us-gaap_OperatingIncomeLoss_label_en-US" xlink:label="lab_us-gaap_OperatingIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Income (Loss) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingIncomeLoss" xlink:to="lab_us-gaap_OperatingIncomeLoss" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLeaseLiabilityCurrent_740a1171-57e5-4040-aaf1-75bbb8319bff_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease liabilities </link:label>
<link:label id="lab_us-gaap_OperatingLeaseLiabilityCurrent_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Lease, Liability, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="lab_us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_0eb7388c-e9e1-4bc8-ad1f-7c54b764e86e_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2023 </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year Two </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_HedgingDesignationAxis_bd40a369-4b25-497d-9526-82a1cda711cd_terseLabel_en-US" xlink:label="lab_us-gaap_HedgingDesignationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Axis] </link:label>
<link:label id="lab_us-gaap_HedgingDesignationAxis_label_en-US" xlink:label="lab_us-gaap_HedgingDesignationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Hedging Designation [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_HedgingDesignationAxis" xlink:to="lab_us-gaap_HedgingDesignationAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensation_ae46c0e7-6cb9-4bb2-8242-e4b315bf421b_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock-based compensation expense </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensation_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Noncash Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensation" xlink:to="lab_us-gaap_ShareBasedCompensation" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_bc83bdb6-18f9-4352-b955-68a9a87c1c7f_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and cash equivalents </link:label>
<link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_label_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents, at Carrying Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_Depreciation_ecf13100-aad2-4d4a-9f42-36f28ba3c040_terseLabel_en-US" xlink:label="lab_us-gaap_Depreciation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation expense </link:label>
<link:label id="lab_us-gaap_Depreciation_label_en-US" xlink:label="lab_us-gaap_Depreciation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Depreciation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Depreciation" xlink:to="lab_us-gaap_Depreciation" xlink:type="arc" order="1"/>
<link:label id="lab_dco_NorthropMember_19cfe93d-e0e3-45bf-9227-7d4559e10fc4_terseLabel_en-US" xlink:label="lab_dco_NorthropMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Northrop </link:label>
<link:label id="lab_dco_NorthropMember_label_en-US" xlink:label="lab_dco_NorthropMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Northrop [Member] </link:label>
<link:label id="lab_dco_NorthropMember_documentation_en-US" xlink:label="lab_dco_NorthropMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Northrop </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_NorthropMember" xlink:href="dco-20211231.xsd#dco_NorthropMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_NorthropMember" xlink:to="lab_dco_NorthropMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_feb02cfe-f0d0-4615-b8c8-4e6aa074c7ae_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] </link:label>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeTaxesPaid_0121dc27-278c-4f1e-b1c1-0f796b65275f_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxesPaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Taxes paid </link:label>
<link:label id="lab_us-gaap_IncomeTaxesPaid_label_en-US" xlink:label="lab_us-gaap_IncomeTaxesPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income Taxes Paid </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxesPaid"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxesPaid" xlink:to="lab_us-gaap_IncomeTaxesPaid" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DerivativeNotionalAmount_6a89792a-8421-4c75-9b97-6e4e28245c42_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Notional amount </link:label>
<link:label id="lab_us-gaap_DerivativeNotionalAmount_label_en-US" xlink:label="lab_us-gaap_DerivativeNotionalAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative, Notional Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeNotionalAmount" xlink:to="lab_us-gaap_DerivativeNotionalAmount" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_ead7efc4-8839-4bca-9da4-b6553db2594e_negatedLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Benefits paid </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Benefit Obligation, Benefits Paid </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:to="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_06700463-7410-475d-b8d4-2c4450d577fa_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Purchases of property and equipment </link:label>
<link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to Acquire Property, Plant, and Equipment </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentMember_101ed1c5-ae3c-4bf7-85a4-4fcf0179bceb_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentMember_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentMember" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanContributionsByEmployer_47341b4a-ed19-4ba3-a5e0-6c691c33beb3_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employer contribution </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanContributionsByEmployer_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Contributions by Employer </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:to="lab_us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_Liabilities_8a136ef6-7b7b-4923-b6ed-819f65523db4_totalLabel_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Liabilities </link:label>
<link:label id="lab_us-gaap_Liabilities_label_en-US" xlink:label="lab_us-gaap_Liabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Liabilities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Liabilities" xlink:to="lab_us-gaap_Liabilities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_GrantsReceivable_5a8279c8-dbc9-481d-826e-290bc374d743_terseLabel_en-US" xlink:label="lab_us-gaap_GrantsReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grants receivable </link:label>
<link:label id="lab_us-gaap_GrantsReceivable_label_en-US" xlink:label="lab_us-gaap_GrantsReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grants Receivable </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrantsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GrantsReceivable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GrantsReceivable" xlink:to="lab_us-gaap_GrantsReceivable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_563a59a8-0d78-49cd-90c5-b60ec64dfd68_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2022 </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Asset, Expected Amortization, Year One </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="arc" order="1"/>
<link:label id="lab_dco_MagneticSealCorporationMember_53821e0c-ce95-4aab-8128-f32b7412cda6_terseLabel_en-US" xlink:label="lab_dco_MagneticSealCorporationMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Magnetic Seal Corporation </link:label>
<link:label id="lab_dco_MagneticSealCorporationMember_label_en-US" xlink:label="lab_dco_MagneticSealCorporationMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Magnetic Seal Corporation [Member] </link:label>
<link:label id="lab_dco_MagneticSealCorporationMember_documentation_en-US" xlink:label="lab_dco_MagneticSealCorporationMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Magnetic Seal Corporation </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_MagneticSealCorporationMember" xlink:href="dco-20211231.xsd#dco_MagneticSealCorporationMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_MagneticSealCorporationMember" xlink:to="lab_dco_MagneticSealCorporationMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_715213d9-e476-47b0-8e5f-0d8438941b63_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Granted (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_af873168-ee58-43e9-a449-049f428ba0e2_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Outstanding </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice_1b944407-153d-434c-b359-cb3dee7fe3cb_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted average exercise price (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_7cf75ab8-a13a-4f3b-8ba4-e9267413a0b3_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expired (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:type="arc" order="1"/>
<link:label id="lab_srt_ConsolidationItemsAxis_82adeeea-93b7-4cce-b854-a707efa310b3_terseLabel_en-US" xlink:label="lab_srt_ConsolidationItemsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidation Items [Axis] </link:label>
<link:label id="lab_srt_ConsolidationItemsAxis_label_en-US" xlink:label="lab_srt_ConsolidationItemsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Consolidation Items [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ConsolidationItemsAxis" xlink:to="lab_srt_ConsolidationItemsAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OperatingLossCarryforwards_570a8559-0d36-431f-a2b7-45523249c2d3_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLossCarryforwards" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net operating loss carryforwards </link:label>
<link:label id="lab_us-gaap_OperatingLossCarryforwards_label_en-US" xlink:label="lab_us-gaap_OperatingLossCarryforwards" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating Loss Carryforwards </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwards"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLossCarryforwards" xlink:to="lab_us-gaap_OperatingLossCarryforwards" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommonStockSharesIssued_09a2b11b-271e-4eab-b2ff-09b3a013c6ff_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, shares issued (in shares) </link:label>
<link:label id="lab_us-gaap_CommonStockSharesIssued_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Shares, Issued </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesIssued" xlink:to="lab_us-gaap_CommonStockSharesIssued" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PreferredStockSharesIssued_b4143348-e9e7-4da8-aa56-ace8b817481a_terseLabel_en-US" xlink:label="lab_us-gaap_PreferredStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred stock, shares issued (in shares) </link:label>
<link:label id="lab_us-gaap_PreferredStockSharesIssued_label_en-US" xlink:label="lab_us-gaap_PreferredStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Preferred Stock, Shares Issued </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesIssued" xlink:to="lab_us-gaap_PreferredStockSharesIssued" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_1491ed11-ee99-4ded-97b3-4ad7ed377dfd_periodStartLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized loss before tax, beginning balance </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_d2012cf9-9271-4814-977f-ea40be0c6f96_periodEndLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized loss before tax, ending balance </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:to="lab_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_d90a88df-6bc4-47c3-9907-2121d586b875_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived intangible assets </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets"/>
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<link:label id="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_576300da-13a3-4ba8-837d-96f6fadf1289_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Assumptions Used </link:label>
<link:label id="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_336e4a8f-fd4c-49ce-bf74-75b04f4a6aeb_verboseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost </link:label>
<link:label id="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Assumptions [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfAssumptionsUsedTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityAddressCityOrTown_6418ac0f-68af-43ff-9ded-fedf2837dcc6_terseLabel_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, City or Town </link:label>
<link:label id="lab_dei_EntityAddressCityOrTown_label_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Address, City or Town </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressCityOrTown"/>
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<link:label id="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt_97bc9c19-f892-4899-a15b-a3056c4e5ab5_terseLabel_en-US" xlink:label="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss on Extinguishment of Debt </link:label>
<link:label id="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt_label_en-US" xlink:label="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gain (Loss) on Extinguishment of Debt </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:to="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EurodollarMember_c2b42561-48c4-493a-881c-400351a31d29_terseLabel_en-US" xlink:label="lab_us-gaap_EurodollarMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Eurodollar Rate </link:label>
<link:label id="lab_us-gaap_EurodollarMember_label_en-US" xlink:label="lab_us-gaap_EurodollarMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Eurodollar [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EurodollarMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EurodollarMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EurodollarMember" xlink:to="lab_us-gaap_EurodollarMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_2941e2a3-1c05-4ca4-aca5-fc9d2f6172d7_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expected Future Benefit Payments Under Pension Plans </link:label>
<link:label id="lab_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Expected Benefit Payments [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RetirementPlanTypeAxis_977f4f1a-bdca-486c-8728-4c4ae6f14d8e_terseLabel_en-US" xlink:label="lab_us-gaap_RetirementPlanTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Type [Axis] </link:label>
<link:label id="lab_us-gaap_RetirementPlanTypeAxis_label_en-US" xlink:label="lab_us-gaap_RetirementPlanTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Type [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetirementPlanTypeAxis" xlink:to="lab_us-gaap_RetirementPlanTypeAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation_2a1c9083-63f1-41b0-8d08-8ca67edf8d48_terseLabel_en-US" xlink:label="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee contribution compensation limit </link:label>
<link:label id="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation_label_en-US" xlink:label="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan Employee Contributions Percentage Of Eligible Compensation </link:label>
<link:label id="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation_documentation_en-US" xlink:label="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Contribution Plan, Employee Contributions, Percentage of Eligible Compensation </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation" xlink:href="dco-20211231.xsd#dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation" xlink:to="lab_dco_DefinedContributionPlanEmployeeContributionsPercentageOfEligibleCompensation" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BalanceSheetLocationAxis_51e39da6-eb01-4e13-9d06-1ab2aa7c7aea_terseLabel_en-US" xlink:label="lab_us-gaap_BalanceSheetLocationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance Sheet Location [Axis] </link:label>
<link:label id="lab_us-gaap_BalanceSheetLocationAxis_label_en-US" xlink:label="lab_us-gaap_BalanceSheetLocationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance Sheet Location [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BalanceSheetLocationAxis" xlink:to="lab_us-gaap_BalanceSheetLocationAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccruedLiabilitiesMember_860f8a03-3420-4b70-b4a2-14ed36b5b86d_terseLabel_en-US" xlink:label="lab_us-gaap_AccruedLiabilitiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued and other liabilities </link:label>
<link:label id="lab_us-gaap_AccruedLiabilitiesMember_label_en-US" xlink:label="lab_us-gaap_AccruedLiabilitiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Liabilities [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedLiabilitiesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedLiabilitiesMember" xlink:to="lab_us-gaap_AccruedLiabilitiesMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets_cad553dd-2b63-44cb-9b6c-336ada60b249_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long term rate of return </link:label>
<link:label id="lab_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long Term Return On Assets </link:label>
<link:label id="lab_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long Term Return on Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets"/>
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<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_ee3a4916-d44c-4a16-9639-66ebece90ce7_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2021 </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, to be Paid, Year One </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_a2ad4ce6-eb6c-4248-9eef-bffa98bf8d24_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred tax expense (benefit) </link:label>
<link:label id="lab_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract"/>
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<link:label id="lab_us-gaap_LossContingenciesByNatureOfContingencyAxis_2f2a878f-0f48-41e0-a10a-a26cc68900f0_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency Nature [Axis] </link:label>
<link:label id="lab_us-gaap_LossContingenciesByNatureOfContingencyAxis_label_en-US" xlink:label="lab_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingency Nature [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
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<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_04d53c2a-cc74-449f-a5f1-53a36197e98a_totalLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total purchase price allocation </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_f22e7263-b9fa-4f06-b2b4-890fc63d4f98_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gross purchase price </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
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<link:label id="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves_341be0d1-2305-4129-a55a-17d74e8d1f84_terseLabel_en-US" xlink:label="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Changes in tax reserves </link:label>
<link:label id="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves_label_en-US" xlink:label="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation Tax Reserves </link:label>
<link:label id="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves_documentation_en-US" xlink:label="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation Tax Reserves </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_EffectiveIncomeTaxRateReconciliationTaxReserves" xlink:href="dco-20211231.xsd#dco_EffectiveIncomeTaxRateReconciliationTaxReserves"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_EffectiveIncomeTaxRateReconciliationTaxReserves" xlink:to="lab_dco_EffectiveIncomeTaxRateReconciliationTaxReserves" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_71ac1928-a670-49d8-a36c-a3e578f42581_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2022 </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Expected Future Benefit Payment, Year One </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
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<link:label id="lab_us-gaap_RetainedEarningsAccumulatedDeficit_a0300f04-5d1b-42b6-bfa5-531138385a9e_terseLabel_en-US" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retained earnings </link:label>
<link:label id="lab_us-gaap_RetainedEarningsAccumulatedDeficit_label_en-US" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retained Earnings (Accumulated Deficit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_e2397e01-acc4-4414-a0f1-84fcf3b0ed23_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expiration period from date of grant </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_0f5deaf3-7d40-48fa-b802-63b24e019ecf_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Stockholders' Equity [Abstract] </link:label>
<link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Stockholders' Equity [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_00757e69-7073-4177-b3b9-3f159b7a6889_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee stock purchase plan (in shares) </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Issued During Period, Shares, Employee Stock Purchase Plans </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityFilerCategory_d82e5e37-5d0e-41a8-8c4d-a1a53ca0074d_terseLabel_en-US" xlink:label="lab_dei_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Filer Category </link:label>
<link:label id="lab_dei_EntityFilerCategory_label_en-US" xlink:label="lab_dei_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Filer Category </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityFilerCategory"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFilerCategory" xlink:to="lab_dei_EntityFilerCategory" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DefinedBenefitPlanNumberOfActivePlans_ad34cd85-ec8a-47ac-bb22-5dcf709286c3_terseLabel_en-US" xlink:label="lab_dco_DefinedBenefitPlanNumberOfActivePlans" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Number Of Active Plans </link:label>
<link:label id="lab_dco_DefinedBenefitPlanNumberOfActivePlans_label_en-US" xlink:label="lab_dco_DefinedBenefitPlanNumberOfActivePlans" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Number Of Active Plans </link:label>
<link:label id="lab_dco_DefinedBenefitPlanNumberOfActivePlans_documentation_en-US" xlink:label="lab_dco_DefinedBenefitPlanNumberOfActivePlans" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Number Of Active Plans </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DefinedBenefitPlanNumberOfActivePlans" xlink:href="dco-20211231.xsd#dco_DefinedBenefitPlanNumberOfActivePlans"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DefinedBenefitPlanNumberOfActivePlans" xlink:to="lab_dco_DefinedBenefitPlanNumberOfActivePlans" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_40b67dcd-e0ef-4e3f-94ca-fc9fe88e16d7_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Risk-free interest rate </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OrderOrProductionBacklogMember_61d77ba9-2028-4361-ba56-7065817ff90a_terseLabel_en-US" xlink:label="lab_us-gaap_OrderOrProductionBacklogMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Backlog </link:label>
<link:label id="lab_us-gaap_OrderOrProductionBacklogMember_label_en-US" xlink:label="lab_us-gaap_OrderOrProductionBacklogMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Order or Production Backlog [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OrderOrProductionBacklogMember" xlink:to="lab_us-gaap_OrderOrProductionBacklogMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ConcentrationRiskTable_e5046565-d87a-4f85-80d2-b08ed334e995_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk [Table] </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskTable_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="lab_us-gaap_ConcentrationRiskTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InventoryDisclosureAbstract_fa0fd078-dbee-424f-8685-b02ea8eaa531_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory Disclosure [Abstract] </link:label>
<link:label id="lab_us-gaap_InventoryDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_InventoryDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryDisclosureAbstract" xlink:to="lab_us-gaap_InventoryDisclosureAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RepaymentsOfLinesOfCredit_32449a6e-21c4-4ad7-be31-b0d981a8ec0f_terseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of lines of credit </link:label>
<link:label id="lab_us-gaap_RepaymentsOfLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Lines of Credit </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfLinesOfCredit" xlink:to="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LocationTwoMember_c14126c9-cad3-4f74-8838-2f001df52091_terseLabel_en-US" xlink:label="lab_dco_LocationTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Casmalia and West Covina, California </link:label>
<link:label id="lab_dco_LocationTwoMember_label_en-US" xlink:label="lab_dco_LocationTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Location Two [Member] </link:label>
<link:label id="lab_dco_LocationTwoMember_documentation_en-US" xlink:label="lab_dco_LocationTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Location 2 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LocationTwoMember" xlink:href="dco-20211231.xsd#dco_LocationTwoMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LocationTwoMember" xlink:to="lab_dco_LocationTwoMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_fa132295-e8df-4b6c-9230-b9f32b9747b2_terseLabel_en-US" xlink:label="lab_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived Intangible Assets (Excluding Goodwill) </link:label>
<link:label id="lab_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_label_en-US" xlink:label="lab_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Indefinite-lived Intangible Assets (Excluding Goodwill) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:to="lab_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_59ee3768-7a55-428f-96ba-52c34949b552_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2022 </link:label>
<link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Liability, to be Paid, Year Two </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:to="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity_43ee009b-cdfe-42b4-9e56-2695cd5c9e1d_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from sale-leaseback </link:label>
<link:label id="lab_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity_label_en-US" xlink:label="lab_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds from Lease Payment, Sales-Type and Direct Financing Leases, Investing Activity </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity" xlink:to="lab_us-gaap_ProceedsFromLeasePaymentSalesTypeAndDirectFinancingLeasesInvestingActivity" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_2875034b-e5bf-4196-9161-6985ab5529f9_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets by Major Class [Axis] </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets by Major Class [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dei_AmendmentFlag_b6c49b4c-1fb0-4dda-9605-3b8f8217a33c_terseLabel_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amendment Flag </link:label>
<link:label id="lab_dei_AmendmentFlag_label_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amendment Flag </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AmendmentFlag"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AmendmentFlag" xlink:to="lab_dei_AmendmentFlag" xlink:type="arc" order="1"/>
<link:label id="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets_d65be7a7-33dc-443f-90cc-c7c1e0d9ad18_terseLabel_en-US" xlink:label="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating lease right-of-use assets </link:label>
<link:label id="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets_label_en-US" xlink:label="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Right-Of-Use Assets </link:label>
<link:label id="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets_documentation_en-US" xlink:label="lab_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Right-Of-Use Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets" xlink:href="dco-20211231.xsd#dco_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAssets"/>
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<link:label id="lab_us-gaap_StatementEquityComponentsAxis_7fb7d6ba-b815-433e-a45f-0c13843f8437_terseLabel_en-US" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Components [Axis] </link:label>
<link:label id="lab_us-gaap_StatementEquityComponentsAxis_label_en-US" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Equity Components [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="lab_us-gaap_StatementEquityComponentsAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_MovementInValuationAllowancesAndReservesRollForward_617ad059-e750-4b56-b9d1-9306eeeaf987_terseLabel_en-US" xlink:label="lab_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] </link:label>
<link:label id="lab_us-gaap_MovementInValuationAllowancesAndReservesRollForward_label_en-US" xlink:label="lab_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward"/>
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<link:label id="lab_us-gaap_ConcentrationRiskTypeDomain_b7d1d392-b32f-4f96-b2e1-5d72a2633a40_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Type [Domain] </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskTypeDomain_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Type [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
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<link:label id="lab_dco_DeferredTaxAssetsAccruedExpenses_e42f2e4f-c8e0-4bbd-b322-374f77636022_terseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsAccruedExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued expenses </link:label>
<link:label id="lab_dco_DeferredTaxAssetsAccruedExpenses_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsAccruedExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Accrued Expenses </link:label>
<link:label id="lab_dco_DeferredTaxAssetsAccruedExpenses_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsAccruedExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Accrued Expenses </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxAssetsAccruedExpenses" xlink:href="dco-20211231.xsd#dco_DeferredTaxAssetsAccruedExpenses"/>
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<link:label id="lab_us-gaap_DisaggregationOfRevenueTable_e30e7f99-d4a9-469e-99a0-af885e135678_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disaggregation of Revenue [Table] </link:label>
<link:label id="lab_us-gaap_DisaggregationOfRevenueTable_label_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Disaggregation of Revenue [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisaggregationOfRevenueTable"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_1b6088bd-9841-4a85-a7ad-07ed3f1a1eff_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Plan assets </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations"/>
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<link:label id="lab_us-gaap_InventoryNet_ff8daba6-fdb0-4cf2-8646-6d62ae0381ea_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories </link:label>
<link:label id="lab_us-gaap_InventoryNet_495afa7e-06f1-4542-b9a2-746adffea680_totalLabel_en-US" xlink:label="lab_us-gaap_InventoryNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total </link:label>
<link:label id="lab_us-gaap_InventoryNet_label_en-US" xlink:label="lab_us-gaap_InventoryNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryNet" xlink:to="lab_us-gaap_InventoryNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_c7d739ef-fb5d-4ee5-8cb2-8745adf02204_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Financial Information by Reportable Segment </link:label>
<link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Segment Reporting Information, by Segment [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_bea1bb93-abc7-4b24-843a-7d8f97041b7a_verboseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Granted (in shares) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod"/>
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<link:label id="lab_us-gaap_GrantsReceivableCurrent_5fa0ef7f-f66a-45f2-86e4-f2a6e26354fc_terseLabel_en-US" xlink:label="lab_us-gaap_GrantsReceivableCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grants receivable, current </link:label>
<link:label id="lab_us-gaap_GrantsReceivableCurrent_label_en-US" xlink:label="lab_us-gaap_GrantsReceivableCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Grants Receivable, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrantsReceivableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GrantsReceivableCurrent"/>
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<link:label id="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_e53ec5a8-1db8-41cd-93f4-c530f1dc8a84_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Federal </link:label>
<link:label id="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_label_en-US" xlink:label="lab_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Federal Income Tax Expense (Benefit) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_688e2c7a-252d-478c-a342-b8fe6a51da6c_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Expired (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice"/>
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<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_33dad077-b5b6-4b14-a826-b09d8f04d458_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Thereafter </link:label>
<link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_label_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Lessee, Operating Lease, Liability, to be Paid, after Year Five </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
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<link:label id="lab_us-gaap_ValuationAllowancesAndReservesRecoveries_c7b5a2b1-68b4-4aa6-a65f-ef7896ded46d_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesRecoveries" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Recoveries </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesRecoveries_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesRecoveries" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves, Addition, Recovery </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesRecoveries" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesRecoveries"/>
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<link:label id="lab_srt_ProductOrServiceAxis_328d4f83-f337-41e8-ae2f-674ac1a4edb6_terseLabel_en-US" xlink:label="lab_srt_ProductOrServiceAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Product and Service [Axis] </link:label>
<link:label id="lab_srt_ProductOrServiceAxis_label_en-US" xlink:label="lab_srt_ProductOrServiceAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Product and Service [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis"/>
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<link:label id="lab_dco_IncreaseDecreaseinRevenuefromContractwithCustomers_cc758b0a-07c4-4be5-a954-b1507ece876b_terseLabel_en-US" xlink:label="lab_dco_IncreaseDecreaseinRevenuefromContractwithCustomers" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Change in revenue for the period </link:label>
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<link:label id="lab_dco_IncreaseDecreaseinRevenuefromContractwithCustomers_documentation_en-US" xlink:label="lab_dco_IncreaseDecreaseinRevenuefromContractwithCustomers" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Revenue from Contract with Customers </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_IncreaseDecreaseinRevenuefromContractwithCustomers" xlink:href="dco-20211231.xsd#dco_IncreaseDecreaseinRevenuefromContractwithCustomers"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_IncreaseDecreaseinRevenuefromContractwithCustomers" xlink:to="lab_dco_IncreaseDecreaseinRevenuefromContractwithCustomers" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityPublicFloat_286e8540-8be1-49c7-ba50-2b2e9155a9f1_terseLabel_en-US" xlink:label="lab_dei_EntityPublicFloat" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Public Float </link:label>
<link:label id="lab_dei_EntityPublicFloat_label_en-US" xlink:label="lab_dei_EntityPublicFloat" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Public Float </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityPublicFloat" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityPublicFloat"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityPublicFloat" xlink:to="lab_dei_EntityPublicFloat" xlink:type="arc" order="1"/>
<link:label id="lab_dei_DocumentsIncorporatedByReferenceTextBlock_9ebfd367-19c1-4f9c-be21-b65948bed1c3_terseLabel_en-US" xlink:label="lab_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Documents Incorporated by Reference </link:label>
<link:label id="lab_dei_DocumentsIncorporatedByReferenceTextBlock_label_en-US" xlink:label="lab_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Documents Incorporated by Reference [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentsIncorporatedByReferenceTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:to="lab_dei_DocumentsIncorporatedByReferenceTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract_77b8dda1-5860-4064-b8bb-9e89483cdd3e_terseLabel_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Aggregate Intrinsic Value </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract_label_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract] </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract_documentation_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" xlink:href="dco-20211231.xsd#dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" xlink:to="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_0520baa6-5d6a-42fd-b241-40c729574407_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock awards vested (in shares) </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockRepurchasedDuringPeriodShares_d9378f14-cb3b-41e8-a73f-e5d6104088c7_negatedLabel_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock repurchased related to the exercise of stock options and stock awards vested (in shares) </link:label>
<link:label id="lab_us-gaap_StockRepurchasedDuringPeriodShares_label_en-US" xlink:label="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Repurchased During Period, Shares </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockRepurchasedDuringPeriodShares" xlink:to="lab_us-gaap_StockRepurchasedDuringPeriodShares" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_c3ae161b-7079-430b-81b4-3f4f240e7391_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued and other liabilities </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StatementLineItems_f839ef7f-616b-4e1d-841d-565138216b87_terseLabel_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Line Items] </link:label>
<link:label id="lab_us-gaap_StatementLineItems_label_en-US" xlink:label="lab_us-gaap_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementLineItems" xlink:to="lab_us-gaap_StatementLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesDomain_19e50470-52ae-4c4a-b1a2-6c25abef10ce_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesDomain_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain" xlink:to="lab_us-gaap_ValuationAllowancesAndReservesDomain" xlink:type="arc" order="1"/>
<link:label id="lab_dco_CreditFacilitiesMember_33ac2c3f-8fac-46d1-9cf2-0a6f593fb66c_terseLabel_en-US" xlink:label="lab_dco_CreditFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facilities </link:label>
<link:label id="lab_dco_CreditFacilitiesMember_label_en-US" xlink:label="lab_dco_CreditFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facilities [Member] </link:label>
<link:label id="lab_dco_CreditFacilitiesMember_documentation_en-US" xlink:label="lab_dco_CreditFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Credit Facilities [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_CreditFacilitiesMember" xlink:href="dco-20211231.xsd#dco_CreditFacilitiesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_CreditFacilitiesMember" xlink:to="lab_dco_CreditFacilitiesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_0dca2740-3bec-4c0c-893f-c77a285b9ec2_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Contract liabilities </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Contract with Customer, Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:to="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_71c4f875-02b3-4aab-b8d6-6ae1f8bcd8bd_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock awards vested </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DomesticCountryMember_22638bde-c2c2-491d-ac5e-e8b76a14b708_terseLabel_en-US" xlink:label="lab_us-gaap_DomesticCountryMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Federal </link:label>
<link:label id="lab_us-gaap_DomesticCountryMember_label_en-US" xlink:label="lab_us-gaap_DomesticCountryMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Domestic Tax Authority [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticCountryMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DomesticCountryMember" xlink:to="lab_us-gaap_DomesticCountryMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RetirementPlanTypeDomain_7d8aec36-ef1c-418c-b3ea-309094088162_terseLabel_en-US" xlink:label="lab_us-gaap_RetirementPlanTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Type [Domain] </link:label>
<link:label id="lab_us-gaap_RetirementPlanTypeDomain_label_en-US" xlink:label="lab_us-gaap_RetirementPlanTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Plan Type [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetirementPlanTypeDomain" xlink:to="lab_us-gaap_RetirementPlanTypeDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtDisclosureAbstract_a31500e7-4082-468c-bc1e-7871fee646e0_terseLabel_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Disclosure [Abstract] </link:label>
<link:label id="lab_us-gaap_DebtDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Disclosure [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtDisclosureAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtDisclosureAbstract" xlink:to="lab_us-gaap_DebtDisclosureAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dco_CapitalExpenditures_4a963df8-3276-4fd0-b47a-be0d77ed38a5_terseLabel_en-US" xlink:label="lab_dco_CapitalExpenditures" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital Expenditures </link:label>
<link:label id="lab_dco_CapitalExpenditures_label_en-US" xlink:label="lab_dco_CapitalExpenditures" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital Expenditures </link:label>
<link:label id="lab_dco_CapitalExpenditures_documentation_en-US" xlink:label="lab_dco_CapitalExpenditures" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Capital Expenditures </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_CapitalExpenditures" xlink:href="dco-20211231.xsd#dco_CapitalExpenditures"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_CapitalExpenditures" xlink:to="lab_dco_CapitalExpenditures" xlink:type="arc" order="1"/>
<link:label id="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract_b0c7b910-4b38-41bf-810d-02dac3be0ea8_terseLabel_en-US" xlink:label="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted-average number of common shares outstanding </link:label>
<link:label id="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract_label_en-US" xlink:label="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number Of Share Outstanding [Abstract] </link:label>
<link:label id="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract_documentation_en-US" xlink:label="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number Of Share Outstanding [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_WeightedAverageNumberOfShareOutstandingAbstract" xlink:href="dco-20211231.xsd#dco_WeightedAverageNumberOfShareOutstandingAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_WeightedAverageNumberOfShareOutstandingAbstract" xlink:to="lab_dco_WeightedAverageNumberOfShareOutstandingAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis_53eeb53b-b58d-4abe-b0b7-cb85186460dd_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment, Type [Axis] </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-Lived Tangible Asset [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsValuationAllowance_4575b068-9717-4bc7-8753-67b124c4cebe_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Tax credit carryforwards valuation allowance </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsValuationAllowance_2b5b7296-9607-4b4f-afca-c9afde4c0928_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Valuation allowance </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsValuationAllowance_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Valuation Allowance </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="lab_us-gaap_DeferredTaxAssetsValuationAllowance" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CorporateNonSegmentMember_4e968c8b-4760-47b2-baee-4fbfd843af18_verboseLabel_en-US" xlink:label="lab_us-gaap_CorporateNonSegmentMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Corporate Administration </link:label>
<link:label id="lab_us-gaap_CorporateNonSegmentMember_label_en-US" xlink:label="lab_us-gaap_CorporateNonSegmentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Corporate, Non-Segment [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateNonSegmentMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CorporateNonSegmentMember" xlink:to="lab_us-gaap_CorporateNonSegmentMember" xlink:type="arc" order="1"/>
<link:label id="lab_srt_MajorCustomersAxis_9aae0dfc-925b-4df3-b8d3-3f7c92011325_terseLabel_en-US" xlink:label="lab_srt_MajorCustomersAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Major Customers [Axis] </link:label>
<link:label id="lab_srt_MajorCustomersAxis_label_en-US" xlink:label="lab_srt_MajorCustomersAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MajorCustomersAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MajorCustomersAxis" xlink:to="lab_srt_MajorCustomersAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DeferredTaxAssetsEnvironmentalReserves_e49b5017-c720-42a3-b53c-353487a3fb4d_terseLabel_en-US" xlink:label="lab_dco_DeferredTaxAssetsEnvironmentalReserves" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Environmental reserves </link:label>
<link:label id="lab_dco_DeferredTaxAssetsEnvironmentalReserves_label_en-US" xlink:label="lab_dco_DeferredTaxAssetsEnvironmentalReserves" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Environmental Reserves </link:label>
<link:label id="lab_dco_DeferredTaxAssetsEnvironmentalReserves_documentation_en-US" xlink:label="lab_dco_DeferredTaxAssetsEnvironmentalReserves" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets Environmental Reserves </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredTaxAssetsEnvironmentalReserves" xlink:href="dco-20211231.xsd#dco_DeferredTaxAssetsEnvironmentalReserves"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DeferredTaxAssetsEnvironmentalReserves" xlink:to="lab_dco_DeferredTaxAssetsEnvironmentalReserves" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_fce84b6f-fd66-453e-beb6-2c2d727bace2_terseLabel_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee Benefit Plans </link:label>
<link:label id="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Retirement Benefits [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:to="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a6be8893-5420-4107-a93c-c28d2ccd3e64_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="lab_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FairValueByAssetClassAxis_0538d6be-4001-4c26-93d2-6611fb398b10_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByAssetClassAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Class [Axis] </link:label>
<link:label id="lab_us-gaap_FairValueByAssetClassAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByAssetClassAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Asset Class [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByAssetClassAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByAssetClassAxis" xlink:to="lab_us-gaap_FairValueByAssetClassAxis" xlink:type="arc" order="1"/>
<link:label id="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract_204513d4-c147-45c5-8667-7c63a11b4b14_terseLabel_en-US" xlink:label="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right-of-use assets obtained in exchange for lease obligations: </link:label>
<link:label id="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract_label_en-US" xlink:label="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right-Of-Use Assets Obtained In Exchange For Lease Obligations [Abstract] </link:label>
<link:label id="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract_documentation_en-US" xlink:label="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Right-Of-Use Assets Obtained In Exchange For Lease Obligations [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" xlink:href="dco-20211231.xsd#dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" xlink:to="lab_dco_RightOfUseAssetsObtainedInExchangeForLeaseObligationsAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_dei_DocumentAnnualReport_f2e3480e-4ad3-499c-95fc-01e2be934ec5_terseLabel_en-US" xlink:label="lab_dei_DocumentAnnualReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Annual Report </link:label>
<link:label id="lab_dei_DocumentAnnualReport_label_en-US" xlink:label="lab_dei_DocumentAnnualReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Document Annual Report </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentAnnualReport" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentAnnualReport"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentAnnualReport" xlink:to="lab_dei_DocumentAnnualReport" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_VestingAxis_dba306d8-877b-42b8-a710-2b2e83978093_terseLabel_en-US" xlink:label="lab_us-gaap_VestingAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vesting [Axis] </link:label>
<link:label id="lab_us-gaap_VestingAxis_label_en-US" xlink:label="lab_us-gaap_VestingAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vesting [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_VestingAxis"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VestingAxis" xlink:to="lab_us-gaap_VestingAxis" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_83fafd00-f43c-4fcb-b840-9eb6bdb101ef_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current liabilities </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:type="arc" order="1"/>
<link:label id="lab_dco_NumberOfDefinedContributionPlans_13496cd3-6d07-4152-b75e-e92ffbe6d59f_terseLabel_en-US" xlink:label="lab_dco_NumberOfDefinedContributionPlans" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number of company sponsored 401(K) defined contribution plans </link:label>
<link:label id="lab_dco_NumberOfDefinedContributionPlans_label_en-US" xlink:label="lab_dco_NumberOfDefinedContributionPlans" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Defined Contribution Plans </link:label>
<link:label id="lab_dco_NumberOfDefinedContributionPlans_documentation_en-US" xlink:label="lab_dco_NumberOfDefinedContributionPlans" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Number Of Defined Contribution Plans </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_NumberOfDefinedContributionPlans" xlink:href="dco-20211231.xsd#dco_NumberOfDefinedContributionPlans"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_NumberOfDefinedContributionPlans" xlink:to="lab_dco_NumberOfDefinedContributionPlans" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_Assets_0584f9ce-7cf9-4913-8262-3dab4ec3484b_totalLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Assets </link:label>
<link:label id="lab_us-gaap_Assets_33b03d76-302b-446c-a823-3235ff3c8d73_terseLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total Assets </link:label>
<link:label id="lab_us-gaap_Assets_label_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Assets" xlink:to="lab_us-gaap_Assets" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PlanNameDomain_fb96b8d7-4b25-4c80-a303-c7379856adb2_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Plan Name [Domain] </link:label>
<link:label id="lab_us-gaap_PlanNameDomain_label_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Plan Name [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="lab_us-gaap_PlanNameDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InterestPaidNet_74eec790-51c8-4dcb-929f-6318f83f55f0_terseLabel_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest paid </link:label>
<link:label id="lab_us-gaap_InterestPaidNet_label_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Paid, Excluding Capitalized Interest, Operating Activities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestPaidNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPaidNet" xlink:to="lab_us-gaap_InterestPaidNet" xlink:type="arc" order="1"/>
<link:label id="lab_srt_SegmentGeographicalDomain_7f50f4a9-4418-4546-9e93-83fa38a9edee_terseLabel_en-US" xlink:label="lab_srt_SegmentGeographicalDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Domain] </link:label>
<link:label id="lab_srt_SegmentGeographicalDomain_label_en-US" xlink:label="lab_srt_SegmentGeographicalDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Geographical [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_SegmentGeographicalDomain" xlink:to="lab_srt_SegmentGeographicalDomain" xlink:type="arc" order="1"/>
<link:label id="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet_dc8c7877-ec75-4496-9208-dbb457050105_negatedTerseLabel_en-US" xlink:label="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net cash paid upon issuance of common stock under stock plans </link:label>
<link:label id="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet_label_en-US" xlink:label="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments From Issuance of Stock Under Award Plans, Net </link:label>
<link:label id="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet_documentation_en-US" xlink:label="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments From Issuance of Stock Under Award Plans, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet" xlink:href="dco-20211231.xsd#dco_PaymentsFromIssuanceofStockUnderAwardPlansNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet" xlink:to="lab_dco_PaymentsFromIssuanceofStockUnderAwardPlansNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DepreciationAndAmortization_8a1deaff-0aa8-41d5-b258-6cc17599e51a_terseLabel_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation and amortization </link:label>
<link:label id="lab_us-gaap_DepreciationAndAmortization_712d2ed6-0d86-4ab6-bd79-8a244f24e09b_verboseLabel_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation and Amortization Expenses </link:label>
<link:label id="lab_us-gaap_DepreciationAndAmortization_label_en-US" xlink:label="lab_us-gaap_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Depreciation, Depletion and Amortization, Nonproduction </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationAndAmortization"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepreciationAndAmortization" xlink:to="lab_us-gaap_DepreciationAndAmortization" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DerivativeContractTypeDomain_4ddf42f8-e652-4627-ba06-7d75153f8c20_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Contract [Domain] </link:label>
<link:label id="lab_us-gaap_DerivativeContractTypeDomain_label_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Derivative Contract [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeContractTypeDomain" xlink:to="lab_us-gaap_DerivativeContractTypeDomain" xlink:type="arc" order="1"/>
<link:label id="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock_206bee81-b5c1-48dc-9d28-7247b08f5d4d_terseLabel_en-US" xlink:label="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Intangible Assets </link:label>
<link:label id="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock_label_en-US" xlink:label="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long Lived Assets Goodwill And Other Intangible Assets Policy [Policy Text Block] </link:label>
<link:label id="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock_documentation_en-US" xlink:label="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long Lived Assets Goodwill and Other Intangible Assets Policy [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock" xlink:href="dco-20211231.xsd#dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock" xlink:to="lab_dco_LongLivedAssetsGoodwillAndOtherIntangibleAssetsPolicyPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SignificantAccountingPoliciesTextBlock_d4a61cc6-8477-4648-9b39-85e2aa2010de_terseLabel_en-US" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Summary of Significant Accounting Policies </link:label>
<link:label id="lab_us-gaap_SignificantAccountingPoliciesTextBlock_label_en-US" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Significant Accounting Policies [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_429f1b76-0e71-4533-bffd-470919948111_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Remaining performance obligation, period </link:label>
<link:label id="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_label_en-US" xlink:label="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:to="lab_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:type="arc" order="1"/>
<link:label id="lab_srt_CumulativeEffectPeriodOfAdoptionDomain_c296830e-4616-473c-8399-c15f9e6a3879_terseLabel_en-US" xlink:label="lab_srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumulative Effect, Period of Adoption [Domain] </link:label>
<link:label id="lab_srt_CumulativeEffectPeriodOfAdoptionDomain_label_en-US" xlink:label="lab_srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cumulative Effect, Period of Adoption [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:to="lab_srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_c61db39c-fb74-4c54-97b3-571374c337dc_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash (Used in) Provided by Operating Activities </link:label>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FurnitureAndFixturesMember_d65b762c-f4ed-4d29-ac64-7e3cd8bc3974_terseLabel_en-US" xlink:label="lab_us-gaap_FurnitureAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Furniture and equipment </link:label>
<link:label id="lab_us-gaap_FurnitureAndFixturesMember_label_en-US" xlink:label="lab_us-gaap_FurnitureAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Furniture and Fixtures [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FurnitureAndFixturesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FurnitureAndFixturesMember" xlink:to="lab_us-gaap_FurnitureAndFixturesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentTable_e87c5e28-a9f6-4299-ba9b-fd9a167fb0a9_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long-term Debt Instruments [Table] </link:label>
<link:label id="lab_us-gaap_DebtInstrumentTable_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long-term Debt Instruments [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentTable" xlink:to="lab_us-gaap_DebtInstrumentTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_ed8cd3c7-6a92-4543-a77e-2c150cf28ed6_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-deductible book expenses </link:label>
<link:label id="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_c5264940-9289-4ec7-bd7d-9d7cf7bdd5cc_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic (in shares) </link:label>
<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_cbbfbb97-8f1c-49a1-9191-65e5daf806ef_verboseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Basic weighted-average common shares outstanding (in shares) </link:label>
<link:label id="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Basic </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="lab_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EarningsPerShareDiluted_0ee66535-288b-441c-91ef-336745a183d7_verboseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareDiluted" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Diluted earnings per share (in dollars per share) </link:label>
<link:label id="lab_us-gaap_EarningsPerShareDiluted_e125200e-5d63-4142-845b-565a9ff053ca_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareDiluted" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Diluted (in dollars per share) </link:label>
<link:label id="lab_us-gaap_EarningsPerShareDiluted_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareDiluted" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Earnings Per Share, Diluted </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareDiluted"/>
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<link:label id="lab_us-gaap_SegmentDomain_618677be-6771-47a2-a63d-f6f22f888974_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segments [Domain] </link:label>
<link:label id="lab_us-gaap_SegmentDomain_label_en-US" xlink:label="lab_us-gaap_SegmentDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segments [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentDomain" xlink:to="lab_us-gaap_SegmentDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit_f3573725-d5e2-4303-bc16-b6dd31089eed_negatedLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of senior secured revolving credit facility </link:label>
<link:label id="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Repayments of Long-term Lines of Credit </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfLongTermLinesOfCredit"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:to="lab_us-gaap_RepaymentsOfLongTermLinesOfCredit" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_70a62311-6fa0-40fb-ba27-97c9dfa837e7_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Dilutive potential common shares (in shares) </link:label>
<link:label id="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Number Diluted Shares Outstanding Adjustment </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:to="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanServiceCost_a1de7784-e47e-4f6c-b7c6-413c3ceb7451_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanServiceCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Service cost </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanServiceCost_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanServiceCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Service Cost </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanServiceCost" xlink:to="lab_us-gaap_DefinedBenefitPlanServiceCost" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccountingStandardsUpdateExtensibleList_c2f7091c-5f03-4646-bb36-5c3d490dd1c5_terseLabel_en-US" xlink:label="lab_us-gaap_AccountingStandardsUpdateExtensibleList" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounting Standards Update [Extensible List] </link:label>
<link:label id="lab_us-gaap_AccountingStandardsUpdateExtensibleList_label_en-US" xlink:label="lab_us-gaap_AccountingStandardsUpdateExtensibleList" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounting Standards Update [Extensible Enumeration] </link:label>
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<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountingStandardsUpdateExtensibleList" xlink:to="lab_us-gaap_AccountingStandardsUpdateExtensibleList" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_NonUsMember_7aedc626-7bbe-4e08-8c99-6fef45ad92f9_terseLabel_en-US" xlink:label="lab_us-gaap_NonUsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-Us </link:label>
<link:label id="lab_us-gaap_NonUsMember_label_en-US" xlink:label="lab_us-gaap_NonUsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Non-US [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonUsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NonUsMember" xlink:to="lab_us-gaap_NonUsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTax_c389be20-dc0d-4917-b1c7-51543ec932bf_totalLabel_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income, Net of Tax </link:label>
<link:label id="lab_us-gaap_ComprehensiveIncomeNetOfTax_label_en-US" xlink:label="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Attributable to Parent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="lab_us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill_959c913d-f89b-4191-aa76-c850c164db68_terseLabel_en-US" xlink:label="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangibles, Net </link:label>
<link:label id="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill_e20736c1-64c4-4baa-a112-2a522704540c_totalLabel_en-US" xlink:label="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangibles, Net </link:label>
<link:label id="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill_label_en-US" xlink:label="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Intangible Assets, Net (Excluding Goodwill) </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="lab_us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_EmployeeSeveranceMember_51bf7708-04c6-4b92-a6f3-c6a4d4e2c0aa_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeSeveranceMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Severance and Benefits </link:label>
<link:label id="lab_us-gaap_EmployeeSeveranceMember_label_en-US" xlink:label="lab_us-gaap_EmployeeSeveranceMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Employee Severance [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeSeveranceMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeSeveranceMember" xlink:to="lab_us-gaap_EmployeeSeveranceMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_cdbffc8d-375c-4a5c-bc2f-1a1251fcac37_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension Adjustments: </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Net of Tax [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract"/>
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<link:label id="lab_dco_MilitaryandSpaceMember_2fcedb93-9e77-4c5b-916e-69dba8ea76a8_terseLabel_en-US" xlink:label="lab_dco_MilitaryandSpaceMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Military and space </link:label>
<link:label id="lab_dco_MilitaryandSpaceMember_label_en-US" xlink:label="lab_dco_MilitaryandSpaceMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Military and Space [Member] </link:label>
<link:label id="lab_dco_MilitaryandSpaceMember_documentation_en-US" xlink:label="lab_dco_MilitaryandSpaceMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Military and Space [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_MilitaryandSpaceMember" xlink:href="dco-20211231.xsd#dco_MilitaryandSpaceMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_MilitaryandSpaceMember" xlink:to="lab_dco_MilitaryandSpaceMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock_4a322be6-d165-427f-8df9-32f0f76a7531_terseLabel_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Maximum percentage of employee compensation for purchase of common stock </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock_label_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Maximum Percentage of Employee Compensation for Purchase of Common Stock </link:label>
<link:label id="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock_documentation_en-US" xlink:label="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Maximum Percentage of Employee Compensation for Purchase of Common Stock </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock" xlink:href="dco-20211231.xsd#dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock" xlink:to="lab_dco_SharebasedCompensationArrangementbySharebasedPaymentAwardMaximumPercentageofEmployeeCompensationforPurchaseofCommonStock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet_abc250e9-904c-456a-95c7-f51dda37c652_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Taxes </link:label>
<link:label id="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet_label_en-US" xlink:label="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Income Tax Liabilities, Net </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:to="lab_us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessAcquisitionAcquireeDomain_5877aa26-15ca-40d0-8d05-91329df1c909_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition, Acquiree [Domain] </link:label>
<link:label id="lab_us-gaap_BusinessAcquisitionAcquireeDomain_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Acquisition, Acquiree [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="lab_us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_5beda7da-4079-495c-ad25-88c3a5ed2887_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property and equipment </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
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<link:label id="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_d665e9fe-5d50-4308-accc-51a7a7587b37_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Principle Reasons for Variation Between Expected and Effective Tax Rate </link:label>
<link:label id="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncomeAndExpensesLesseeAbstract_9433a8ef-c06e-400d-bb55-8a74d50ec568_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeAndExpensesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance leases expense: </link:label>
<link:label id="lab_us-gaap_IncomeAndExpensesLesseeAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeAndExpensesLesseeAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Income and Expenses, Lessee [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeAndExpensesLesseeAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeAndExpensesLesseeAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeAndExpensesLesseeAbstract" xlink:to="lab_us-gaap_IncomeAndExpensesLesseeAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccountsPayableCurrent_fc51f423-9578-405d-a73e-de33abd81cb0_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts payable </link:label>
<link:label id="lab_us-gaap_AccountsPayableCurrent_label_en-US" xlink:label="lab_us-gaap_AccountsPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Payable, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsPayableCurrent" xlink:to="lab_us-gaap_AccountsPayableCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts_3d4811f1-5d0f-4323-8bab-9d7dd2f09f45_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Allowance for doubtful accounts </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Accounts Receivable, Allowance for Credit Loss </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts"/>
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<link:label id="lab_us-gaap_EntityWideRevenueMajorCustomerLineItems_b13223ef-f849-4097-b6a0-2d7bb4827423_terseLabel_en-US" xlink:label="lab_us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Major Customer [Line Items] </link:label>
<link:label id="lab_us-gaap_EntityWideRevenueMajorCustomerLineItems_label_en-US" xlink:label="lab_us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Revenue, Major Customer [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="lab_us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember_b4859426-6517-41d0-b596-ab48fb403e86_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated Other Comprehensive Loss </link:label>
<link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> AOCI Attributable to Parent [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncreaseDecreaseInInventories_83024c39-6768-4d3c-8cd8-1ff5cb425b73_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInInventories" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInInventories_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInInventories" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Inventories </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInInventories"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInInventories" xlink:to="lab_us-gaap_IncreaseDecreaseInInventories" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CommonStockSharesOutstanding_96cb4fbd-1044-4650-b3bc-8ba73e05ccb8_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, shares outstanding (in shares) </link:label>
<link:label id="lab_us-gaap_CommonStockSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Shares, Outstanding </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesOutstanding" xlink:to="lab_us-gaap_CommonStockSharesOutstanding" xlink:type="arc" order="1"/>
<link:label id="lab_dco_WeightedAverageLeaseTermAbstract_fbad3b05-58d3-4ec9-9747-0ce95f142caf_terseLabel_en-US" xlink:label="lab_dco_WeightedAverageLeaseTermAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Lease Term </link:label>
<link:label id="lab_dco_WeightedAverageLeaseTermAbstract_label_en-US" xlink:label="lab_dco_WeightedAverageLeaseTermAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Lease Term [Abstract] </link:label>
<link:label id="lab_dco_WeightedAverageLeaseTermAbstract_documentation_en-US" xlink:label="lab_dco_WeightedAverageLeaseTermAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Weighted Average Lease Term [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_WeightedAverageLeaseTermAbstract" xlink:href="dco-20211231.xsd#dco_WeightedAverageLeaseTermAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_WeightedAverageLeaseTermAbstract" xlink:to="lab_dco_WeightedAverageLeaseTermAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InventoryRawMaterialsAndSupplies_5f8c727f-f0b5-446f-8b3d-e087545b0e5e_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryRawMaterialsAndSupplies" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Raw materials and supplies </link:label>
<link:label id="lab_us-gaap_InventoryRawMaterialsAndSupplies_label_en-US" xlink:label="lab_us-gaap_InventoryRawMaterialsAndSupplies" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory, Raw Materials and Supplies, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterialsAndSupplies" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryRawMaterialsAndSupplies"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryRawMaterialsAndSupplies" xlink:to="lab_us-gaap_InventoryRawMaterialsAndSupplies" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CostOfGoodsAndServicesSold_015163f9-a571-4615-9f2e-dbb724c8a505_terseLabel_en-US" xlink:label="lab_us-gaap_CostOfGoodsAndServicesSold" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cost of Sales </link:label>
<link:label id="lab_us-gaap_CostOfGoodsAndServicesSold_label_en-US" xlink:label="lab_us-gaap_CostOfGoodsAndServicesSold" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cost of Goods and Services Sold </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSold" xlink:to="lab_us-gaap_CostOfGoodsAndServicesSold" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ExecutivesandDirectorsMember_6a0066f2-c6b7-40ee-ab11-e0c59af3f50c_terseLabel_en-US" xlink:label="lab_dco_ExecutivesandDirectorsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Executives and Directors </link:label>
<link:label id="lab_dco_ExecutivesandDirectorsMember_label_en-US" xlink:label="lab_dco_ExecutivesandDirectorsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Executives and Directors [Member] </link:label>
<link:label id="lab_dco_ExecutivesandDirectorsMember_documentation_en-US" xlink:label="lab_dco_ExecutivesandDirectorsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Executives and Directors [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ExecutivesandDirectorsMember" xlink:href="dco-20211231.xsd#dco_ExecutivesandDirectorsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ExecutivesandDirectorsMember" xlink:to="lab_dco_ExecutivesandDirectorsMember" xlink:type="arc" order="1"/>
<link:label id="lab_dei_EntityCentralIndexKey_04499c5c-62dd-4602-b879-dc4f2ffff9c3_terseLabel_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Central Index Key </link:label>
<link:label id="lab_dei_EntityCentralIndexKey_label_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Entity Central Index Key </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityCentralIndexKey"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCentralIndexKey" xlink:to="lab_dei_EntityCentralIndexKey" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_46afb023-62dd-4b3e-a864-067e96ca8658_terseLabel_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] </link:label>
<link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InterestRateCapMember_8209dd1d-04b7-4bce-8cee-c47b6eee3413_terseLabel_en-US" xlink:label="lab_us-gaap_InterestRateCapMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest rate cap premiums </link:label>
<link:label id="lab_us-gaap_InterestRateCapMember_label_en-US" xlink:label="lab_us-gaap_InterestRateCapMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest Rate Cap [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateCapMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestRateCapMember" xlink:to="lab_us-gaap_InterestRateCapMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsGrossAbstract_b3423aeb-8e41-40a1-9127-9153ec28b305_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsGrossAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred tax assets: </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsGrossAbstract_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsGrossAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Gross [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsGrossAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsGrossAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="lab_us-gaap_DeferredTaxAssetsGrossAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_a582f90d-0e06-4a97-8e06-00ad65220012_negatedLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reductions for tax positions related to prior years </link:label>
<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_label_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:to="lab_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CustomerRelationshipsMember_d476096d-72a7-45c0-9c20-464c390bf471_terseLabel_en-US" xlink:label="lab_us-gaap_CustomerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer relationships </link:label>
<link:label id="lab_us-gaap_CustomerRelationshipsMember_label_en-US" xlink:label="lab_us-gaap_CustomerRelationshipsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Customer Relationships [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CustomerRelationshipsMember" xlink:to="lab_us-gaap_CustomerRelationshipsMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ProductionCostOfContractsCurrent_3e62832f-8940-4c38-8e5e-26689089a607_terseLabel_en-US" xlink:label="lab_dco_ProductionCostOfContractsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Production cost of contracts </link:label>
<link:label id="lab_dco_ProductionCostOfContractsCurrent_label_en-US" xlink:label="lab_dco_ProductionCostOfContractsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Production Cost Of Contracts Current </link:label>
<link:label id="lab_dco_ProductionCostOfContractsCurrent_documentation_en-US" xlink:label="lab_dco_ProductionCostOfContractsCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Costs incurred for certain long-term contracts that require machinery or tools to build the parts as specified within the contract. These costs include production and tooling costs. The production contract costs are recorded to costs of sales using the units of delivery method. </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ProductionCostOfContractsCurrent" xlink:href="dco-20211231.xsd#dco_ProductionCostOfContractsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ProductionCostOfContractsCurrent" xlink:to="lab_dco_ProductionCostOfContractsCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ConcentrationRiskDisclosureTextBlock_ddd894f3-b45e-44f1-a359-d41677bb00dd_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Major Customers and Concentrations of Credit Risk </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:to="lab_us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LossContingenciesLineItems_8e3aa0d6-5293-4a1f-956c-1b3cd448b9da_terseLabel_en-US" xlink:label="lab_us-gaap_LossContingenciesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingencies [Line Items] </link:label>
<link:label id="lab_us-gaap_LossContingenciesLineItems_label_en-US" xlink:label="lab_us-gaap_LossContingenciesLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Loss Contingencies [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingenciesLineItems" xlink:to="lab_us-gaap_LossContingenciesLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpense_b751f1a7-4f7b-4bf6-bd89-a48168947ca0_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred tax assets, tax deferred expense </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpense_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Tax Deferred Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpense"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpense" xlink:to="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpense" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_07a94d42-4ad0-45f4-a0c8-f2e384d7b91c_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property and Equipment, Net </link:label>
<link:label id="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Property, Plant and Equipment Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_590e7bf1-2652-466f-ba2b-a7156b0d37cc_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Long-Term Liabilities </link:label>
<link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Liabilities, Noncurrent </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:to="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_0b95ee0c-6ff3-4e39-bcd8-709a4a2f1066_periodStartLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Beginning benefit obligation </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_c22ad3f7-115b-423f-86da-e901598d691d_periodEndLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Ending benefit obligation </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Benefit Obligation </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:to="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:type="arc" order="1"/>
<link:label id="lab_dco_StockOptionsAndRestrictedStockUnitsMember_be4f915b-769b-429d-adf5-dc9f8c829e4f_terseLabel_en-US" xlink:label="lab_dco_StockOptionsAndRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock options and stock units </link:label>
<link:label id="lab_dco_StockOptionsAndRestrictedStockUnitsMember_label_en-US" xlink:label="lab_dco_StockOptionsAndRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Options And Restricted Stock Units [Member] </link:label>
<link:label id="lab_dco_StockOptionsAndRestrictedStockUnitsMember_documentation_en-US" xlink:label="lab_dco_StockOptionsAndRestrictedStockUnitsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock Options And Restricted Stock Units [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_StockOptionsAndRestrictedStockUnitsMember" xlink:href="dco-20211231.xsd#dco_StockOptionsAndRestrictedStockUnitsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_StockOptionsAndRestrictedStockUnitsMember" xlink:to="lab_dco_StockOptionsAndRestrictedStockUnitsMember" xlink:type="arc" order="1"/>
<link:label id="lab_dco_DeferredCompensationPlanMember_082b6420-6f14-475a-9e80-eb7cc87859de_terseLabel_en-US" xlink:label="lab_dco_DeferredCompensationPlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Compensation Plan </link:label>
<link:label id="lab_dco_DeferredCompensationPlanMember_label_en-US" xlink:label="lab_dco_DeferredCompensationPlanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Compensation Plan [Member] </link:label>
<link:label id="lab_dco_DeferredCompensationPlanMember_documentation_en-US" xlink:label="lab_dco_DeferredCompensationPlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Compensation Plan [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_DeferredCompensationPlanMember" xlink:href="dco-20211231.xsd#dco_DeferredCompensationPlanMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_DeferredCompensationPlanMember" xlink:to="lab_dco_DeferredCompensationPlanMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock_1c79f38b-4369-4d38-bed3-b9067140929d_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long Term Debt </link:label>
<link:label id="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Long-term Debt Instruments [Table Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDebtInstrumentsTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:to="lab_us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_dco_GoodwillAndIntangibleAssetsTable_12700023-a5e7-42af-a3f7-47bc7f542574_terseLabel_en-US" xlink:label="lab_dco_GoodwillAndIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Intangible Assets [Table] </link:label>
<link:label id="lab_dco_GoodwillAndIntangibleAssetsTable_label_en-US" xlink:label="lab_dco_GoodwillAndIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Intangible Assets [Table] </link:label>
<link:label id="lab_dco_GoodwillAndIntangibleAssetsTable_documentation_en-US" xlink:label="lab_dco_GoodwillAndIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill And Intangible Assets [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_GoodwillAndIntangibleAssetsTable" xlink:href="dco-20211231.xsd#dco_GoodwillAndIntangibleAssetsTable"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_GoodwillAndIntangibleAssetsTable" xlink:to="lab_dco_GoodwillAndIntangibleAssetsTable" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentLineItems_8b66f559-a63f-47fe-83ef-00e0c690ee39_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Line Items] </link:label>
<link:label id="lab_us-gaap_DebtInstrumentLineItems_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentLineItems" xlink:to="lab_us-gaap_DebtInstrumentLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_dei_TradingSymbol_5f05e57f-4f5f-4a8d-9bbf-73b1c7d7236e_terseLabel_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trading Symbol </link:label>
<link:label id="lab_dei_TradingSymbol_label_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Trading Symbol </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_TradingSymbol"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_TradingSymbol" xlink:to="lab_dei_TradingSymbol" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_4a272dfe-007e-4cf2-9d8c-8fdfc97b0495_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued and Other Liabilities </link:label>
<link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accounts Payable and Accrued Liabilities Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:to="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax_ac6d590f-9a0b-4c6b-b118-393f860b834e_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Actuarial gain (loss) arising during the period, tax benefit </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax"/>
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<link:label id="lab_us-gaap_DeferredTaxLiabilitiesOther_137ab062-dc74-4ba0-9f32-7fab78e91d3b_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesOther" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesOther_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Other </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesOther"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesOther" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesOther" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets_aee6ebc2-7d98-45d4-8c15-afabd29fe829_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other assets </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Other Operating Assets </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:to="lab_us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentUnamortizedPremium_6f77b3d0-437e-4a12-ae81-31142b04b4d9_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedPremium" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Interest rate cap hedge premium </link:label>
<link:label id="lab_us-gaap_DebtInstrumentUnamortizedPremium_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedPremium" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Unamortized Premium </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedPremium" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnamortizedPremium"/>
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<link:label id="lab_us-gaap_SaleLeasebackTransactionNetBookValue_121b72ce-9923-4319-ad4c-5b0516bcd81e_terseLabel_en-US" xlink:label="lab_us-gaap_SaleLeasebackTransactionNetBookValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale leaseback transaction, carrying value </link:label>
<link:label id="lab_us-gaap_SaleLeasebackTransactionNetBookValue_label_en-US" xlink:label="lab_us-gaap_SaleLeasebackTransactionNetBookValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Sale Leaseback Transaction, Net Book Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleLeasebackTransactionNetBookValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleLeasebackTransactionNetBookValue"/>
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<link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_4e9b3b1f-b545-48e9-98a8-3c4483dd86d3_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Third Anniversary </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Tranche Three [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:to="lab_us-gaap_ShareBasedCompensationAwardTrancheThreeMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax_b19562d5-ed0c-40be-874e-04e4b517e80c_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Amortization </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax </link:label>
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<link:label id="lab_us-gaap_GoodwillGross_0a092fff-d4b9-4b13-9a19-467dc6a66a43_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gross goodwill </link:label>
<link:label id="lab_us-gaap_GoodwillGross_label_en-US" xlink:label="lab_us-gaap_GoodwillGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill, Gross </link:label>
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<link:label id="lab_us-gaap_LongTermDebtNoncurrent_1e527e5f-5279-44b5-bb23-8a86ca7aac17_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total long-term debt, less current portion </link:label>
<link:label id="lab_us-gaap_LongTermDebtNoncurrent_label_en-US" xlink:label="lab_us-gaap_LongTermDebtNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Long-term Debt, Excluding Current Maturities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
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<link:label id="lab_us-gaap_ScheduleOfGoodwillTable_e0e9c4ad-62ca-4b6e-acf9-0797366c6b44_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfGoodwillTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Goodwill [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfGoodwillTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfGoodwillTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Goodwill [Table] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfGoodwillTable"/>
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<link:label id="lab_us-gaap_AllocatedShareBasedCompensationExpense_c171baa9-2cd0-4000-9667-f962a3d740db_terseLabel_en-US" xlink:label="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based compensation expense </link:label>
<link:label id="lab_us-gaap_AllocatedShareBasedCompensationExpense_label_en-US" xlink:label="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Payment Arrangement, Expense </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
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<link:label id="lab_dco_NoncashGainsLossesonExtinguishmentofDebt_01565143-4462-4fdf-8574-a5aedff31f17_negatedTerseLabel_en-US" xlink:label="lab_dco_NoncashGainsLossesonExtinguishmentofDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash loss on extinguishment of debt </link:label>
<link:label id="lab_dco_NoncashGainsLossesonExtinguishmentofDebt_label_en-US" xlink:label="lab_dco_NoncashGainsLossesonExtinguishmentofDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash Gains (Losses) on Extinguishment of Debt </link:label>
<link:label id="lab_dco_NoncashGainsLossesonExtinguishmentofDebt_documentation_en-US" xlink:label="lab_dco_NoncashGainsLossesonExtinguishmentofDebt" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Noncash Gains (Losses) on Extinguishment of Debt </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_NoncashGainsLossesonExtinguishmentofDebt" xlink:href="dco-20211231.xsd#dco_NoncashGainsLossesonExtinguishmentofDebt"/>
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<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_9984c53b-9713-469e-9e24-3a34a9e54589_verboseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Exercisable </link:label>
<link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_label_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
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<link:label id="lab_us-gaap_PayablesAndAccrualsAbstract_6e083988-ae09-4dc3-99b3-78bb0e53b5ea_terseLabel_en-US" xlink:label="lab_us-gaap_PayablesAndAccrualsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payables and Accruals [Abstract] </link:label>
<link:label id="lab_us-gaap_PayablesAndAccrualsAbstract_label_en-US" xlink:label="lab_us-gaap_PayablesAndAccrualsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payables and Accruals [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PayablesAndAccrualsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PayablesAndAccrualsAbstract"/>
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<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_9973543a-bc23-4ae3-a303-c1ea7ca2629f_negatedTotalLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Total liabilities assumed </link:label>
<link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
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<link:label id="lab_us-gaap_ConstructionInProgressMember_04fe37cb-d7e2-4adf-8823-7113c5cbbcff_terseLabel_en-US" xlink:label="lab_us-gaap_ConstructionInProgressMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Construction in progress </link:label>
<link:label id="lab_us-gaap_ConstructionInProgressMember_label_en-US" xlink:label="lab_us-gaap_ConstructionInProgressMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Construction in Progress [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConstructionInProgressMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConstructionInProgressMember" xlink:to="lab_us-gaap_ConstructionInProgressMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_0267995b-35e0-48ac-bd53-c7e80011a521_periodStartLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents at Beginning of Year </link:label>
<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_47cf1402-8617-41dd-b947-3305d833a601_periodEndLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash and Cash Equivalents at End of Year </link:label>
<link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_label_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
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<link:label id="lab_us-gaap_DamageFromFireExplosionOrOtherHazardMember_be892802-1826-4036-88a1-9030c0b755dd_terseLabel_en-US" xlink:label="lab_us-gaap_DamageFromFireExplosionOrOtherHazardMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Damage from Facility Fire </link:label>
<link:label id="lab_us-gaap_DamageFromFireExplosionOrOtherHazardMember_label_en-US" xlink:label="lab_us-gaap_DamageFromFireExplosionOrOtherHazardMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Damage from Fire, Explosion or Other Hazard [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DamageFromFireExplosionOrOtherHazardMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DamageFromFireExplosionOrOtherHazardMember"/>
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<link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_7b6a7c18-649f-478d-ab8a-a586a113bf2e_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common stock, par value (in dollars per share) </link:label>
<link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_label_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Common Stock, Par or Stated Value Per Share </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
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<link:label id="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsLineItems_bddeb4cc-352c-417e-8d2b-799ab5c5d50a_terseLabel_en-US" xlink:label="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Benefit Obligations Weighted Average Assumptions [Line Items] </link:label>
<link:label id="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsLineItems_label_en-US" xlink:label="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule Of Benefit Obligations Weighted Average Assumptions [Line Items] </link:label>
<link:label id="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsLineItems_documentation_en-US" xlink:label="lab_dco_ScheduleOfBenefitObligationsWeightedAverageAssumptionsLineItems" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Benefit Obligations Weighted Average Assumptions [Line Items] </link:label>
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<link:label id="lab_us-gaap_DefinedBenefitPlanDisclosureLineItems_e9b8afe5-6d1f-4651-a7b2-f164000b36b9_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Disclosure [Line Items] </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanDisclosureLineItems_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan Disclosure [Line Items] </link:label>
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<link:label id="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_87f043d7-371b-4d5c-8f1b-0d245c60af35_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Comprehensive Income [Abstract] </link:label>
<link:label id="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Statement of Comprehensive Income [Abstract] </link:label>
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<link:label id="lab_us-gaap_AssetsCurrentAbstract_f5b67e09-5eaf-4ff1-99d1-71a59abc20a8_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Current Assets </link:label>
<link:label id="lab_us-gaap_AssetsCurrentAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Assets, Current [Abstract] </link:label>
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<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsGross_6f3ae3ac-5b48-486e-9cb4-39fa1aaa8301_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Gross Carrying Amount </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsGross_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Gross </link:label>
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<link:label id="lab_us-gaap_PaymentsForHedgeFinancingActivities_4dcc2104-da59-4fb3-8e82-3fd50a710788_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForHedgeFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments made for interest rate hedge </link:label>
<link:label id="lab_us-gaap_PaymentsForHedgeFinancingActivities_label_en-US" xlink:label="lab_us-gaap_PaymentsForHedgeFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments for Hedge, Financing Activities </link:label>
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<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_028cb234-644a-4639-a1a7-37e9b182e854_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-lived assets </link:label>
<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finite-Lived Intangible Assets, Net [Abstract] </link:label>
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<link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_0645c14e-6cb6-4c26-8f51-23cac8a5ecc0_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Other Intangible Assets </link:label>
<link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table Text Block] </link:label>
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<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_bd7ddfe0-997b-4f24-82e7-badf66055669_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stock options exercised (in shares) </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_6bee77ff-c117-48c5-b391-f1a1802c4564_negatedLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Exercised (in shares) </link:label>
<link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period </link:label>
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<link:label id="lab_dco_ProceedsFromExerciseOfStockOptionsAndOtherStockIssuances_d0efdfc4-7ae5-492a-a679-beb7ab5c9326_terseLabel_en-US" xlink:label="lab_dco_ProceedsFromExerciseOfStockOptionsAndOtherStockIssuances" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cash received from the exercise of options </link:label>
<link:label id="lab_dco_ProceedsFromExerciseOfStockOptionsAndOtherStockIssuances_label_en-US" xlink:label="lab_dco_ProceedsFromExerciseOfStockOptionsAndOtherStockIssuances" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Proceeds From Exercise Of Stock Options And Other Stock Issuances </link:label>
<link:label id="lab_dco_ProceedsFromExerciseOfStockOptionsAndOtherStockIssuances_documentation_en-US" xlink:label="lab_dco_ProceedsFromExerciseOfStockOptionsAndOtherStockIssuances" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> The cash inflow associated with the amount received from holders exercising their stock options and the cash inflow from other equity not otherwise defined in the taxonomy. </link:label>
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<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax_2507f0ff-9a85-4475-94c5-e6991308ea4b_totalLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Net of Tax </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax_40e95ce5-ebde-4dac-b346-835d145aa8f3_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other comprehensive income (loss), net of tax </link:label>
<link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Comprehensive Income (Loss), Net of Tax </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
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<link:label id="lab_us-gaap_LitigationReserve_a0e74978-6f9f-472e-8766-09aebad49807_terseLabel_en-US" xlink:label="lab_us-gaap_LitigationReserve" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated litigation liability </link:label>
<link:label id="lab_us-gaap_LitigationReserve_label_en-US" xlink:label="lab_us-gaap_LitigationReserve" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Estimated Litigation Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationReserve" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LitigationReserve"/>
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<link:label id="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock_a2e7f05d-d5a6-4393-b5d4-c879770f15c9_terseLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Shareholders' Equity </link:label>
<link:label id="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Stockholders' Equity Note Disclosure [Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
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<link:label id="lab_dco_DebtInstrumentBasisSpreadonFixedRateBaseRate_3c8299c5-8cb6-4f3b-9fbd-8175e676a6ac_terseLabel_en-US" xlink:label="lab_dco_DebtInstrumentBasisSpreadonFixedRateBaseRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Spread on base rate </link:label>
<link:label id="lab_dco_DebtInstrumentBasisSpreadonFixedRateBaseRate_label_en-US" xlink:label="lab_dco_DebtInstrumentBasisSpreadonFixedRateBaseRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Basis Spread on Fixed Rate, Base Rate </link:label>
<link:label id="lab_dco_DebtInstrumentBasisSpreadonFixedRateBaseRate_documentation_en-US" xlink:label="lab_dco_DebtInstrumentBasisSpreadonFixedRateBaseRate" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Basis Spread on Fixed Rate, Base Rate </link:label>
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<link:label id="lab_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_2061668e-37ac-4cde-befb-52b14f5f6de8_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Reductions for lapse of statute of limitations </link:label>
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<link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_c37a64f9-0cbb-456b-aca3-d05a2ba70949_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> 2026 </link:label>
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<link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_716c0dc4-1493-4f09-8c15-a37647b81c77_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Weighted Average Number of Shares Outstanding Excluded from Computation of Diluted Earnings </link:label>
<link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] </link:label>
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<link:label id="lab_dei_AuditorFirmId_2cedba1b-ae4e-46a4-b88f-fcc709be0655_terseLabel_en-US" xlink:label="lab_dei_AuditorFirmId" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Auditor Firm ID </link:label>
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<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities_c11c12c7-0f15-46b0-bc1d-3bffb2defd54_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities </link:label>
<link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
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<link:label id="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_74636f7b-a26c-4eb6-9f43-9c5311d09d56_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Change in benefit obligation </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward"/>
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<link:label id="lab_us-gaap_BuildingAndBuildingImprovementsMember_0bcdf65f-5419-488a-b0bc-0280375ea967_terseLabel_en-US" xlink:label="lab_us-gaap_BuildingAndBuildingImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Buildings and improvements </link:label>
<link:label id="lab_us-gaap_BuildingAndBuildingImprovementsMember_label_en-US" xlink:label="lab_us-gaap_BuildingAndBuildingImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Building and Building Improvements [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BuildingAndBuildingImprovementsMember" xlink:to="lab_us-gaap_BuildingAndBuildingImprovementsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_35147a6e-c596-470f-832a-cbf318fe2d7b_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Changes in Assets and Liabilities: </link:label>
<link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Increase (Decrease) in Operating Capital [Abstract] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired_4dab8a79-20bb-4211-97f3-fdb9c258bfa5_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves, Business Acquired </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired" xlink:to="lab_us-gaap_ValuationAllowancesAndReservesReservesOfBusinessesAcquired" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_f5be9fec-c03c-478f-a7c6-6638b98def7a_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Vested (in dollars per share) </link:label>
<link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessesGross_f8bdabac-2ac8-4b7b-9a3e-3c21a0c15d9b_terseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessesGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to acquire business </link:label>
<link:label id="lab_us-gaap_PaymentsToAcquireBusinessesGross_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireBusinessesGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Payments to Acquire Businesses, Gross </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireBusinessesGross" xlink:to="lab_us-gaap_PaymentsToAcquireBusinessesGross" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset_63808461-ca28-4baf-af50-602fe6e4ace2_terseLabel_en-US" xlink:label="lab_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Carrying value of impaired assets </link:label>
<link:label id="lab_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset_label_en-US" xlink:label="lab_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Impaired Assets to be Disposed of by Method Other than Sale, Carrying Value of Asset </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset" xlink:to="lab_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_4a958d97-39e8-4ee4-890f-d3e394367581_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of credit facility, maximum borrowing capacity </link:label>
<link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Line of Credit Facility, Maximum Borrowing Capacity </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability_7605bb1d-4ad0-4db7-9f16-57a73b9a8653_terseLabel_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Operating cash flows from finance leases </link:label>
<link:label id="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Finance Lease, Interest Payment on Liability </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseInterestPaymentOnLiability"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:to="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:type="arc" order="1"/>
<link:label id="lab_dco_NewTermLoanMaturingDecember202024Member_699c451a-17b4-40aa-bf44-a6fada7b72ab_terseLabel_en-US" xlink:label="lab_dco_NewTermLoanMaturingDecember202024Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Term Loan </link:label>
<link:label id="lab_dco_NewTermLoanMaturingDecember202024Member_label_en-US" xlink:label="lab_dco_NewTermLoanMaturingDecember202024Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Term Loan Maturing December 20, 2024 [Member] </link:label>
<link:label id="lab_dco_NewTermLoanMaturingDecember202024Member_documentation_en-US" xlink:label="lab_dco_NewTermLoanMaturingDecember202024Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Term Loan Maturing December 20, 2024 [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_NewTermLoanMaturingDecember202024Member" xlink:href="dco-20211231.xsd#dco_NewTermLoanMaturingDecember202024Member"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_NewTermLoanMaturingDecember202024Member" xlink:to="lab_dco_NewTermLoanMaturingDecember202024Member" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_SegmentReportingInformationLineItems_699ac45d-94c2-4e36-9428-e79cf5764b3c_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting Information [Line Items] </link:label>
<link:label id="lab_us-gaap_SegmentReportingInformationLineItems_label_en-US" xlink:label="lab_us-gaap_SegmentReportingInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Segment Reporting Information [Line Items] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingInformationLineItems"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems" xlink:to="lab_us-gaap_SegmentReportingInformationLineItems" xlink:type="arc" order="1"/>
<link:label id="lab_dco_ElectronicSystemsMember_51f104ec-fc5c-4954-936e-b20a8b601b38_terseLabel_en-US" xlink:label="lab_dco_ElectronicSystemsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Electronic Systems </link:label>
<link:label id="lab_dco_ElectronicSystemsMember_label_en-US" xlink:label="lab_dco_ElectronicSystemsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Electronic Systems [Member] </link:label>
<link:label id="lab_dco_ElectronicSystemsMember_documentation_en-US" xlink:label="lab_dco_ElectronicSystemsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Electronic Systems [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_dco_ElectronicSystemsMember" xlink:href="dco-20211231.xsd#dco_ElectronicSystemsMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dco_ElectronicSystemsMember" xlink:to="lab_dco_ElectronicSystemsMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_ab05e081-92e4-4d40-8c5e-d2379770519a_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Discount rate </link:label>
<link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:to="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DebtInstrumentNameDomain_7a8ab2c7-9177-4726-ad18-9df86135b6b7_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Name [Domain] </link:label>
<link:label id="lab_us-gaap_DebtInstrumentNameDomain_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Debt Instrument, Name [Domain] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="lab_us-gaap_DebtInstrumentNameDomain" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_FederalFundsEffectiveSwapRateMember_d8ea0427-afe2-4594-89d6-b36bae45d2a1_terseLabel_en-US" xlink:label="lab_us-gaap_FederalFundsEffectiveSwapRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Federal Funds Rate </link:label>
<link:label id="lab_us-gaap_FederalFundsEffectiveSwapRateMember_label_en-US" xlink:label="lab_us-gaap_FederalFundsEffectiveSwapRateMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Fed Funds Effective Rate Overnight Index Swap Rate [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsEffectiveSwapRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalFundsEffectiveSwapRateMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FederalFundsEffectiveSwapRateMember" xlink:to="lab_us-gaap_FederalFundsEffectiveSwapRateMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_OtherAssetsCurrent_0f160c48-8686-4b60-b49e-ff629a852ac2_terseLabel_en-US" xlink:label="lab_us-gaap_OtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other current assets </link:label>
<link:label id="lab_us-gaap_OtherAssetsCurrent_label_en-US" xlink:label="lab_us-gaap_OtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Other Assets, Current </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsCurrent"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetsCurrent" xlink:to="lab_us-gaap_OtherAssetsCurrent" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill_f0303deb-1550-48c9-8aa8-72447502d047_negatedLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Goodwill </link:label>
<link:label id="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Liabilities, Goodwill </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill" xlink:to="lab_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill" xlink:type="arc" order="1"/>
<link:label id="lab_dco_SeniorSecuredTermLoanMember_814d37a5-30ad-432c-aff1-a2466a22746e_terseLabel_en-US" xlink:label="lab_dco_SeniorSecuredTermLoanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Term loans </link:label>
<link:label id="lab_dco_SeniorSecuredTermLoanMember_label_en-US" xlink:label="lab_dco_SeniorSecuredTermLoanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Secured Term Loan [Member] </link:label>
<link:label id="lab_dco_SeniorSecuredTermLoanMember_documentation_en-US" xlink:label="lab_dco_SeniorSecuredTermLoanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Senior Secured Term Loan [Member] </link:label>
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<link:label id="lab_dco_NewCreditFacilitiesMember_a26198f5-a78d-4fb7-b0bc-47c004f3ba2f_terseLabel_en-US" xlink:label="lab_dco_NewCreditFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Credit Facilities </link:label>
<link:label id="lab_dco_NewCreditFacilitiesMember_label_en-US" xlink:label="lab_dco_NewCreditFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Credit Facilities [Member] </link:label>
<link:label id="lab_dco_NewCreditFacilitiesMember_documentation_en-US" xlink:label="lab_dco_NewCreditFacilitiesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> New Credit Facilities [Member] </link:label>
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<link:label id="lab_dco_AccruedBenefitLiability_079766eb-0277-475d-9a7e-26e9c39d08e8_terseLabel_en-US" xlink:label="lab_dco_AccruedBenefitLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accumulated benefit obligations </link:label>
<link:label id="lab_dco_AccruedBenefitLiability_label_en-US" xlink:label="lab_dco_AccruedBenefitLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Benefit Liability </link:label>
<link:label id="lab_dco_AccruedBenefitLiability_documentation_en-US" xlink:label="lab_dco_AccruedBenefitLiability" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Accrued Benefit Liability </link:label>
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<link:label id="lab_us-gaap_ValuationAllowancesAndReservesBalance_fbd520b6-b8d0-407a-8077-39e39e3c1007_periodStartLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesBalance" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance at Beginning of Period </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesBalance_7db4877f-7bf8-47b0-9bca-1bcac18be58e_periodEndLabel_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesBalance" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Balance at  End of Period </link:label>
<link:label id="lab_us-gaap_ValuationAllowancesAndReservesBalance_label_en-US" xlink:label="lab_us-gaap_ValuationAllowancesAndReservesBalance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
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<link:label id="lab_us-gaap_CostOfSalesMember_ff7e56b9-9417-4121-acc4-c96484b87bd1_terseLabel_en-US" xlink:label="lab_us-gaap_CostOfSalesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cost of Sales </link:label>
<link:label id="lab_us-gaap_CostOfSalesMember_label_en-US" xlink:label="lab_us-gaap_CostOfSalesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Cost of Sales [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostOfSalesMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfSalesMember" xlink:to="lab_us-gaap_CostOfSalesMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_InventoryPolicyTextBlock_e40dca40-b7b1-4862-883e-afe6aa869eaf_terseLabel_en-US" xlink:label="lab_us-gaap_InventoryPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventories </link:label>
<link:label id="lab_us-gaap_InventoryPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap_InventoryPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Inventory, Policy [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryPolicyTextBlock"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryPolicyTextBlock" xlink:to="lab_us-gaap_InventoryPolicyTextBlock" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal_7c7bfdbd-3ff1-4c13-8536-8e122dc902b8_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Federal and state net operating loss carryforwards </link:label>
<link:label id="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Deferred Tax Assets, Operating Loss Carryforwards, State and Local </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal" xlink:to="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_PensionPlansDefinedBenefitMember_318918a5-219c-407f-9790-3acdb50c5690_terseLabel_en-US" xlink:label="lab_us-gaap_PensionPlansDefinedBenefitMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension Plan </link:label>
<link:label id="lab_us-gaap_PensionPlansDefinedBenefitMember_label_en-US" xlink:label="lab_us-gaap_PensionPlansDefinedBenefitMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Pension Plan [Member] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
<link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PensionPlansDefinedBenefitMember" xlink:to="lab_us-gaap_PensionPlansDefinedBenefitMember" xlink:type="arc" order="1"/>
<link:label id="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements_4f7b005b-077b-4236-abe1-4ed1fd39db25_terseLabel_en-US" xlink:label="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Restructuring Charges </link:label>
<link:label id="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements_label_en-US" xlink:label="lab_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Costs Associated with Exit or Disposal Activity or Restructuring, Ongoing Benefit Arrangement [Policy Text Block] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements"/>
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<link:label id="lab_us-gaap_ConcentrationRiskByBenchmarkAxis_3018ba10-426a-4eb5-bcc5-2ff53f24c3f0_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Benchmark [Axis] </link:label>
<link:label id="lab_us-gaap_ConcentrationRiskByBenchmarkAxis_label_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Concentration Risk Benchmark [Axis] </link:label>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
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<link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_75e32ca4-0407-41be-9d6b-d127134a21cc_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table] </link:label>
<link:label id="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US"> Schedule of Finite-Lived Intangible Assets [Table] </link:label>
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12 Subsequent Filings that Reference this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/22/24  Ducommun Inc./DE                  10-K       12/31/23  114:13M                                    Workiva Inc Wde… FA01/FA
11/08/23  Ducommun Inc./DE                  10-Q        9/30/23   65:6.7M                                   Workiva Inc Wde… FA01/FA
 8/03/23  Ducommun Inc./DE                  10-Q        7/01/23   65:6.6M                                   Workiva Inc Wde… FA01/FA
 5/17/23  Ducommun Inc./DE                  424B5                  1:1.6M                                   Donnelley … Solutions/FA
 5/15/23  Ducommun Inc./DE                  424B5                  1:1.6M                                   Donnelley … Solutions/FA
 5/04/23  Ducommun Inc./DE                  10-Q        4/01/23   62:6.1M                                   Workiva Inc Wde… FA01/FA
 2/16/23  Ducommun Inc./DE                  10-K       12/31/22  114:14M                                    Workiva Inc Wde… FA01/FA
11/07/22  Ducommun Inc./DE                  10-Q       10/01/22   65:7M                                     Workiva Inc Wde… FA01/FA
11/07/22  Ducommun Inc./DE                  S-3                    5:653K                                   Donnelley … Solutions/FA
 8/04/22  Ducommun Inc./DE                  10-Q        7/02/22   65:6.6M                                   Workiva Inc Wde… FA01/FA
 5/03/22  Ducommun Inc./DE                  10-Q        4/02/22   61:5.4M                                   Workiva Inc Wde… FA01/FA
 4/20/22  Ducommun Inc./DE                  S-8         4/20/22    4:73K                                    Donnelley … Solutions/FA


23 Previous Filings that this Filing References

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12/20/21  Ducommun Inc./DE                  8-K:1,2,8,912/16/21   12:423K                                   Donnelley … Solutions/FA
12/16/21  Ducommun Inc./DE                  8-K:1,2,7,912/15/21   12:623K                                   Donnelley … Solutions/FA
11/02/21  Ducommun Inc./DE                  10-Q       10/02/21   57:5.5M                                   Workiva Inc Wde… FA01/FA
 3/08/21  Ducommun Inc./DE                  8-K:5,9     3/05/21   11:147K                                   Donnelley … Solutions/FA
 7/30/20  Ducommun Inc./DE                  10-Q        6/27/20   71:7M                                     Workiva Inc Wde… FA01/FA
 3/20/20  Ducommun Inc./DE                  DEF 14A     5/06/20    1:4.4M                                   Donnelley … Solutions/FA
 2/20/20  Ducommun Inc./DE                  10-K       12/31/19  120:14M                                    Workiva Inc Wde… FA01/FA
12/20/19  Ducommun Inc./DE                  8-K:1,2,9  12/20/19    2:137K                                   Donnelley … Solutions/FA
11/26/19  Ducommun Inc./DE                  S-8        11/26/19    4:198K                                   Donnelley … Solutions/FA
10/09/19  Ducommun Inc./DE                  8-K:1,2,7,910/07/19    3:457K                                   Donnelley … Solutions/FA
 6/28/19  Ducommun Inc./DE                  8-K:5,9     6/26/19    2:62K                                    Donnelley … Solutions/FA
11/26/18  Ducommun Inc./DE                  8-K:1,2,8,911/21/18    3:1.7M                                   Donnelley … Solutions/FA
 5/10/18  Ducommun Inc./DE                  S-8         5/10/18    4:132K                                   Donnelley … Solutions/FA
 3/23/18  Ducommun Inc./DE                  DEF 14A     5/02/18    1:1.1M                                   Donnelley … Solutions/FA
 2/26/18  Ducommun Inc./DE                  8-K:5,9     2/21/18    2:17K                                    Donnelley … Solutions/FA
 9/11/17  Ducommun Inc./DE                  8-K:1,2,7,9 9/11/17    3:416K                                   Donnelley … Solutions/FA
 3/06/17  Ducommun Inc./DE                  10-K       12/31/16  113:13M                                    Workiva Inc Wde… FA01/FA
 1/27/17  Ducommun Inc./DE                  8-K:1,9     1/23/17    3:86K                                    Donnelley … Solutions/FA
 1/09/17  Ducommun Inc./DE                  8-K:5,9     1/03/17    3:46K                                    Donnelley … Solutions/FA
 3/22/13  Ducommun Inc./DE                  8-K:5,9     3/19/13    2:64K                                    Donnelley … Solutions/FA
 2/22/10  Ducommun Inc./DE                  10-K       12/31/09    9:1.1M                                   Donnelley … Solutions/FA
 3/04/04  Ducommun Inc./DE                  10-K       12/31/03   11:953K                                   Donnelley … Solutions/FA
 3/04/99  Ducommun Inc./DE                  10-K405    12/31/98    9:115K                                   Bowne - Biv/FA
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Filing Submission 0001628280-22-003518   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)

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