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National Presto Industries Inc – ‘10-K’ for 12/31/19 – ‘EX-101.LAB’

On:  Tuesday, 3/10/20, at 6:16pm ET   ·   As of:  3/11/20   ·   For:  12/31/19   ·   Accession #:  1562762-20-111   ·   File #:  1-02451

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

 3/11/20  National Presto Industries Inc    10-K       12/31/19   92:8.1M                                   Certent, Inc./FA

Annual Report   —   Form 10-K   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-K        Annual Report                                       HTML    884K 
 2: EX-4        Instrument Defining the Rights of Security Holders  HTML     30K 
 3: EX-21       Subsidiaries List                                   HTML     27K 
 4: EX-31.1     Certification -- §302 - SOA'02                      HTML     32K 
 5: EX-31.2     Certification -- §302 - SOA'02                      HTML     32K 
 6: EX-32.1     Certification -- §906 - SOA'02                      HTML     27K 
 7: EX-32.2     Certification -- §906 - SOA'02                      HTML     27K 
41: R1          Document And Entity Information                     HTML     76K 
88: R2          Consolidated Balance Sheets                         HTML    151K 
58: R3          Consolidated Balance Sheets (Parenthetical)         HTML     37K 
31: R4          Consolidated Statements Of Comprehensive Income     HTML     91K 
42: R5          Consolidated Statements Of Cash Flows               HTML    138K 
89: R6          Consolidated Statements Of Stockholders' Equity     HTML     52K 
59: R7          Consolidated Statements Of Stockholders' Equity     HTML     28K 
                (Parenthetical)                                                  
30: R8          Summary Of Significant Accounting Policies          HTML    147K 
45: R9          Inventories                                         HTML     50K 
23: R10         Accrued Liabilities                                 HTML     30K 
34: R11         Treasury Stock                                      HTML     28K 
85: R12         Net Earnings Per Share                              HTML     27K 
57: R13         Stock-Based Compensation                            HTML     71K 
22: R14         401(k) Plan                                         HTML     31K 
33: R15         Income Taxes                                        HTML    134K 
84: R16         Commitments And Contingencies                       HTML     27K 
56: R17         Concentrations                                      HTML     33K 
21: R18         Environmental                                       HTML     42K 
35: R19         Business Segments                                   HTML    150K 
79: R20         Leases                                              HTML     63K 
72: R21         Interim Financial Information                       HTML    143K 
20: R22         Line Of Credit And Commercial Letters Of Credit     HTML     30K 
52: R23         Discontinued Operations                             HTML     75K 
78: R24         Divestiture                                         HTML     29K 
71: R25         Business Acquisition                                HTML     68K 
19: R26         Other                                               HTML     29K 
51: R27         Subsequent Event                                    HTML     29K 
80: R28         Valuation And Qualifying Accounts                   HTML     79K 
70: R29         Summary Of Significant Accounting Policies          HTML    200K 
                (Policy)                                                         
53: R30         Summary Of Significant Accounting Policies          HTML     88K 
                (Tables)                                                         
82: R31         Inventories (Tables)                                HTML     44K 
36: R32         Stock-Based Compensation (Tables)                   HTML     62K 
24: R33         Income Taxes (Tables)                               HTML    136K 
54: R34         Environmental (Tables)                              HTML     36K 
83: R35         Business Segments (Tables)                          HTML    141K 
37: R36         Leases (Tables)                                     HTML     60K 
25: R37         Interim Financial Information (Tables)              HTML    140K 
55: R38         Discontinued Operations (Tables)                    HTML     73K 
81: R39         Business Acquisition (Tables)                       HTML     63K 
67: R40         Summary Of Significant Accounting Policies          HTML    165K 
                (Narrative) (Details)                                            
76: R41         Summary Of Significant Accounting Policies (Timing  HTML     33K 
                Of Performance Obligation) (Narrative) (Details)                 
46: R42         Summary Of Significant Accounting Policies          HTML     41K 
                (Summary Of The Amortized Costs And Fair Values Of               
                Marketable Securities) (Details)                                 
14: R43         Summary Of Significant Accounting Policies          HTML     32K 
                (Schedule Of Changes In Product Warranty                         
                Liability) (Details)                                             
68: R44         Inventories (Narrative) (Details)                   HTML     43K 
77: R45         Inventories (Schedule Of Potential Impact Of LIFO   HTML     33K 
                Valuation to FIFO Valuation) (Details)                           
47: R46         Accrued Liabilities (Narrative) (Details)           HTML     37K 
15: R47         Treasury Stock (Narrative) (Details)                HTML     29K 
69: R48         Stock-Based Compensation (Narrative) (Details)      HTML     54K 
75: R49         Stock-Based Compensation (Schedule Of Activity For  HTML     47K 
                Non-Vested Restricted Stock) (Details)                           
91: R50         401(k) Plan (Narrative) (Details)                   HTML     40K 
64: R51         Income Taxes (Narrative) (Details)                  HTML     36K 
27: R52         Income Taxes (Schedule Of Provision For Income      HTML     46K 
                Taxes) (Details)                                                 
40: R53         Income Taxes (Reconciliation Of Statutory Rate to   HTML     42K 
                Effective Rate) (Details)                                        
90: R54         Income Taxes (Schedule Of Deferred Tax Assets And   HTML     62K 
                Liabilities) (Details)                                           
63: R55         Income Taxes (Reconciliation Of Unrecognized Tax    HTML     40K 
                Benefits) (Details)                                              
26: R56         Concentrations (Narrative) (Details)                HTML     38K 
39: R57         Environmental (Narrative) (Details)                 HTML     28K 
92: R58         Environmental (Schedule Of Expected Future          HTML     42K 
                Payments Of Environmental Matters) (Details)                     
62: R59         Business Segments (Narrative) (Details)             HTML     31K 
18: R60         Business Segments (Summary Of Business Segment      HTML     67K 
                Information) (Details)                                           
49: R61         Leases (Narrative) (Details)                        HTML     43K 
74: R62         Leases (Summary of Lease Cost) (Details)            HTML     31K 
66: R63         Leases (Summary of Operating Lease Liability        HTML     43K 
                Maturities) (Details)                                            
17: R64         Leases (Summary of Lease Income from Operating      HTML     40K 
                Lease Payments) (Details)                                        
48: R65         Interim Financial Information (Schedule Of          HTML     59K 
                Quarterly Financial Information) (Details)                       
73: R66         Line Of Credit And Commercial Letters Of Credit     HTML     35K 
                (Narrative) (Details)                                            
65: R67         Discontinued Operations (Narrative) (Details)       HTML     61K 
16: R68         Discontinued Operations (Summary Of Discontinued    HTML     69K 
                Operations) (Details)                                            
50: R69         Discontinued Operations (Summary of Major Classes   HTML     35K 
                of Assets and Liabilities) (Details)                             
43: R70         Divestiture (Narrative) (Details)                   HTML     39K 
28: R71         Business Acquisition (Narrative) (Details)          HTML     53K 
60: R72         Business Acquisition (Schedule of Assets Acquired   HTML     59K 
                and Liabilities Assumed) (Details)                               
86: R73         Business Acquisition (Schedule of Pro Forma         HTML     34K 
                Results of Operations) (Details)                                 
44: R74         Other (Narrative) (Details)                         HTML     32K 
29: R75         Subsequent Event (Narrative) (Details)              HTML     33K 
61: R76         Valuation And Qualifying Accounts (Details)         HTML     36K 
32: XML         IDEA XML File -- Filing Summary                      XML    169K 
38: EXCEL       IDEA Workbook of Financial Reports                  XLSX     95K 
 8: EX-101.INS  XBRL Instance -- npk-20191231                        XML   2.25M 
10: EX-101.CAL  XBRL Calculations -- npk-20191231_cal                XML    241K 
11: EX-101.DEF  XBRL Definitions -- npk-20191231_def                 XML    403K 
12: EX-101.LAB  XBRL Labels -- npk-20191231_lab                      XML   1.08M 
13: EX-101.PRE  XBRL Presentations -- npk-20191231_pre               XML    892K 
 9: EX-101.SCH  XBRL Schema -- npk-20191231                          XSD    152K 
87: ZIP         XBRL Zipped Folder -- 0001562762-20-000111-xbrl      Zip    167K

‘EX-101.LAB’   —   XBRL Labels — npk-20191231_lab

This Exhibit is an XBRL XML File.

                                                                                                                                                                                
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DocumentAndEntityInformationAbstract_lbl" xml:lang="en-US"> Document And Entity Information [Abstract] </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US"> Statement [Line Items] </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentType_lbl" xml:lang="en-US"> Document Type </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US"> Current Fiscal Year End Date </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentPeriodEndDate_lbl" xml:lang="en-US"> Document Period End Date </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalYearFocus_lbl" xml:lang="en-US"> Document Fiscal Year Focus </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFileNumber" xlink:to="dei_EntityFileNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFileNumber_lbl" xml:lang="en-US"> Entity File Number </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityRegistrantName_lbl" xml:lang="en-US"> Entity Registrant Name </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityIncorporationStateCountryName" xlink:label="dei_EntityIncorporationStateCountryName"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryName" xlink:to="dei_EntityIncorporationStateCountryName_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityIncorporationStateCountryName_lbl" xml:lang="en-US"> Entity Incorporation, State Country Name </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityTaxIdentificationNumber" xlink:to="dei_EntityTaxIdentificationNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xml:lang="en-US"> Entity Tax Identification Number </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine1" xlink:to="dei_EntityAddressAddressLine1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressAddressLine1_lbl" xml:lang="en-US"> Entity Address, Address Line One </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCityOrTown" xlink:to="dei_EntityAddressCityOrTown_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressCityOrTown_lbl" xml:lang="en-US"> Entity Address, City or Town </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressStateOrProvince" xlink:to="dei_EntityAddressStateOrProvince_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressStateOrProvince_lbl" xml:lang="en-US"> Entity Address, State or Province </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressPostalZipCode_lbl" xml:lang="en-US"> Entity Address, Postal Zip Code </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CityAreaCode_lbl" xml:lang="en-US"> City Area Code </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LocalPhoneNumber_lbl" xml:lang="en-US"> Local Phone Number </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US"> Trading Symbol </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xml:lang="en-US"> Entity Well-known Seasoned Issuer </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityVoluntaryFilers_lbl" xml:lang="en-US"> Entity Voluntary Filers </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCurrentReportingStatus_lbl" xml:lang="en-US"> Entity Current Reporting Status </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFilerCategory_lbl" xml:lang="en-US"> Entity Filer Category </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntitySmallBusiness_lbl" xml:lang="en-US"> Entity Small Business </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityEmergingGrowthCompany" xlink:to="dei_EntityEmergingGrowthCompany_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xml:lang="en-US"> Entity Emerging Growth Company </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityShellCompany_lbl" xml:lang="en-US"> Entity Shell Company </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityPublicFloat_lbl" xml:lang="en-US"> Entity Public Float </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xml:lang="en-US"> Entity Common Stock, Shares Outstanding </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCentralIndexKey_lbl" xml:lang="en-US"> Entity Central Index Key </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xml:lang="en-US"> Document Fiscal Period Focus </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US"> Amendment Flag </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US"> Consolidated Balance Sheets [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US"> ASSETS </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xml:lang="en-US"> Assets, Current [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xml:lang="en-US"> CURRENT ASSETS: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US"> Cash and cash equivalents </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="us-gaap_MarketableSecuritiesCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesCurrent" xlink:to="us-gaap_MarketableSecuritiesCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesCurrent_lbl" xml:lang="en-US"> Marketable securities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsReceivableGross" xlink:label="us-gaap_AccountsReceivableGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableGross" xlink:to="us-gaap_AccountsReceivableGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableGross_lbl" xml:lang="en-US"> Accounts Receivable, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsReceivableGross_lbl" xml:lang="en-US"> Accounts receivable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US"> Allowance for Doubtful Accounts Receivable </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US"> Less allowance for doubtful accounts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US"> Accounts receivable, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US"> Accounts receivable, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US"> Accounts receivable, net </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryNetAbstract" xlink:label="us-gaap_InventoryNetAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNetAbstract" xlink:to="us-gaap_InventoryNetAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryNetAbstract_lbl" xml:lang="en-US"> Inventories: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:to="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl" xml:lang="en-US"> Inventory, Finished Goods, Net of Reserves </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl" xml:lang="en-US"> Finished goods </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryWorkInProcess" xlink:label="us-gaap_InventoryWorkInProcess"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWorkInProcess" xlink:to="us-gaap_InventoryWorkInProcess_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryWorkInProcess_lbl" xml:lang="en-US"> Work in process </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryWorkInProcess_lbl" xml:lang="en-US"> Work in process </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryRawMaterialsAndSupplies" xlink:label="us-gaap_InventoryRawMaterialsAndSupplies"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterialsAndSupplies" xlink:to="us-gaap_InventoryRawMaterialsAndSupplies_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryRawMaterialsAndSupplies_lbl" xml:lang="en-US"> Inventory, Raw Materials and Supplies, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryRawMaterialsAndSupplies_lbl" xml:lang="en-US"> Raw materials and supplies </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US"> Inventory, Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US"> Total inventory </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Assets, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xml:lang="en-US"> Assets held for sale </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NotesAndLoansReceivableNetCurrent" xlink:label="us-gaap_NotesAndLoansReceivableNetCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesAndLoansReceivableNetCurrent" xlink:to="us-gaap_NotesAndLoansReceivableNetCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesAndLoansReceivableNetCurrent_lbl" xml:lang="en-US"> Notes, Loans and Financing Receivable, Net, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesAndLoansReceivableNetCurrent_lbl" xml:lang="en-US"> Notes receivable, current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NotesAndLoansReceivableNetCurrent_lbl" xml:lang="en-US"> Notes receivable, current, related to option agreement </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xml:lang="en-US"> Other Assets Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xml:lang="en-US"> Other current assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US"> Total current assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US"> Total current assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentNetAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNetAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNetAbstract_lbl" xml:lang="en-US"> PROPERTY, PLANT AND EQUIPMENT: </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNetAbstract_lbl" xml:lang="en-US"> PROPERTY, PLANT AND EQUIPMENT: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Land" xlink:label="us-gaap_Land"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Land" xlink:to="us-gaap_Land_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Land_lbl" xml:lang="en-US"> Land </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_Land_lbl" xml:lang="en-US"> Land and land improvements </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BuildingsAndImprovementsGross" xlink:label="us-gaap_BuildingsAndImprovementsGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BuildingsAndImprovementsGross" xlink:to="us-gaap_BuildingsAndImprovementsGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BuildingsAndImprovementsGross_lbl" xml:lang="en-US"> Buildings and Improvements, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BuildingsAndImprovementsGross_lbl" xml:lang="en-US"> Buildings </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MachineryAndEquipmentGross" xlink:label="us-gaap_MachineryAndEquipmentGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentGross" xlink:to="us-gaap_MachineryAndEquipmentGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MachineryAndEquipmentGross_lbl" xml:lang="en-US"> Machinery and Equipment, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_MachineryAndEquipmentGross_lbl" xml:lang="en-US"> Machinery and equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xml:lang="en-US"> Property, Plant and Equipment, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xml:lang="en-US"> PROPERTY, PLANT AND EQUIPMENT </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Less allowance for depreciation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Less allowance for depreciation and amortization </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> Property, Plant and Equipment, Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US"> PROPERTY, PLANT AND EQUIPMENT, NET </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill_lbl"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US"> GOODWILL </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US"> Goodwill </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US"> INTANGIBLE ASSETS, net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US"> INTANGIBLE ASSETS, net </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NotesAndLoansReceivableNetNoncurrent" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesAndLoansReceivableNetNoncurrent" xlink:to="us-gaap_NotesAndLoansReceivableNetNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent_lbl" xml:lang="en-US"> NOTES RECEIVABLE </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent_lbl" xml:lang="en-US"> Note receivable, related to license agreement </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent_lbl" xml:lang="en-US"> NOTES RECEIVABLE </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xml:lang="en-US"> RIGHT-OF-USE LEASE ASSETS </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xml:lang="en-US"> RIGHT-OF-USE LEASE ASSETS </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xml:lang="en-US"> Right of use assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxAssetsNet" xlink:to="us-gaap_DeferredIncomeTaxAssetsNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet_lbl" xml:lang="en-US"> Deferred Tax Assets, Net, Noncurrent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet_lbl" xml:lang="en-US"> DEFERRED INCOME TAXES </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xml:lang="en-US"> OTHER ASSETS </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xml:lang="en-US"> OTHER ASSETS </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> Assets, total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> Total assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US"> Total assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US"> Liabilities and Equity [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US"> LIABILITIES AND STOCKHOLDERS’ EQUITY </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAbstract" xlink:label="us-gaap_LiabilitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAbstract" xlink:to="us-gaap_LiabilitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAbstract_lbl" xml:lang="en-US"> Liabilities Abstract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LiabilitiesAbstract_lbl" xml:lang="en-US"> LIABILITIES </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xml:lang="en-US"> Liabilities, Current [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xml:lang="en-US"> CURRENT LIABILITIES: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xml:lang="en-US"> Accounts payable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="us-gaap_AccruedIncomeTaxesCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedIncomeTaxesCurrent" xlink:to="us-gaap_AccruedIncomeTaxesCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedIncomeTaxesCurrent_lbl" xml:lang="en-US"> Federal and state income taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccruedIncomeTaxesCurrent_lbl" xml:lang="en-US"> Federal and state income taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xml:lang="en-US"> Operating Lease, Liability, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xml:lang="en-US"> Lease liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xml:lang="en-US"> Accrued liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US"> Total current liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US"> Total current liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xml:lang="en-US"> LEASE LIABILITIES - NON-CURRENT </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xml:lang="en-US"> LEASE LIABILITIES - NON-CURRENT </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xml:lang="en-US"> Lease liability </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US"> Liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US"> Total liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US"> STOCKHOLDERS' EQUITY </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common stock, $1 par value: Authorized: 12,000,000 Issued: 7,440,518 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US"> Common stock, $1 par value: Authorized: 12,000,000 shares at December 31, 2019 and 2018; Issued: 7,440,518 shares at December 31, 2019 and 2018; Outstanding: 7,006,323 and 6,981,080 shares at December 31, 2019 and 2018, respectively </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US"> Paid-in capital </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US"> Retained earnings </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income Loss Net Of Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xml:lang="en-US"> Accumulated other comprehensive income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityBeforeTreasuryStock" xlink:label="us-gaap_StockholdersEquityBeforeTreasuryStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityBeforeTreasuryStock" xlink:to="us-gaap_StockholdersEquityBeforeTreasuryStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityBeforeTreasuryStock_lbl" xml:lang="en-US"> Stockholders' Equity before Treasury Stock </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquityBeforeTreasuryStock_lbl" xml:lang="en-US"> Stockholders' equity before treasury stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="us-gaap_TreasuryStockValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValue" xlink:to="us-gaap_TreasuryStockValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Treasury stock, at cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US"> Less treasury stock, at cost, 434,195 and 459,438 shares at December 31, 2019 and 2018, respectively </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Total stockholders' equity </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US"> Total stockholders' equity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> Liabilities and Stockholders' Equity, Total </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US"> Total liabilities and stockholders' equity </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xml:lang="en-US"> Common stock, par value </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US"> Common stock, shares authorized </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US"> Common stock, shares issued </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Common Stock, Shares, Outstanding </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Balance, shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Balance, shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US"> Common stock, shares outstanding </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="us-gaap_TreasuryStockShares"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockShares" xlink:to="us-gaap_TreasuryStockShares_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US"> Treasury Stock, Shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US"> Treasury stock, at cost </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xml:lang="en-US"> Consolidated Statements Of Comprehensive Income [Abstract] </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Revenues" xlink:to="us-gaap_Revenues_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US"> Revenues </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US"> External net sales </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xml:lang="en-US"> Revenue from Related Parties </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xml:lang="en-US"> Net Sales </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xml:lang="en-US"> Material sales, related party </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfGoodsAndServicesSold" xlink:to="us-gaap_CostOfGoodsAndServicesSold_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xml:lang="en-US"> Cost of sales </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xml:lang="en-US"> Cost of sales </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GrossProfit_lbl" xml:lang="en-US"> Gross Profit </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_GrossProfit_lbl" xml:lang="en-US"> Gross profit </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GrossProfit_lbl" xml:lang="en-US"> Gross profit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xml:lang="en-US"> Selling and general expenses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xml:lang="en-US"> Selling and general expenses </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Intangibles amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Intangibles amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US"> Amortization expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="us-gaap_GainLossOnSaleOfBusiness"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfBusiness" xlink:to="us-gaap_GainLossOnSaleOfBusiness_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnSaleOfBusiness_lbl" xml:lang="en-US"> Loss (gain) on Disposition of Business </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainLossOnSaleOfBusiness_lbl" xml:lang="en-US"> Net loss (gain) and impairment on divestiture of businesses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:label="us-gaap_GainLossOnSaleOfBusiness_lbl" xml:lang="en-US"> Loss on divestiture, net </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US"> Operating Income (Loss) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US"> Operating profit </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US"> Operating profit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US"> Other Nonoperating Income (Expense) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US"> Other income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US"> Other income (expense) </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xml:lang="en-US"> Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xml:lang="en-US"> Earnings from continuing operations before provision for income taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Income tax provision </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Provision for income taxes from continuing operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Total tax provision </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Earnings from continuing operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US"> Earnings from continuing operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" xlink:to="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Earnings from discontinued operations, net of tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Earnings from discontinued operations, net of tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_lbl" xml:lang="en-US"> Earnings (loss) from discontinued operations, net of tax </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net earnings </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net earnings </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US"> Net earnings </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xml:lang="en-US"> Weighted average common shares outstanding: </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xml:lang="en-US"> Weighted average common shares outstanding: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_lbl" xml:lang="en-US"> Weighted Average Number of Shares Outstanding, Basic and Diluted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_lbl" xml:lang="en-US"> Basic and diluted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_lbl" xml:lang="en-US"> Weighted average shares outstanding (basic and diluted) </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xml:lang="en-US"> Net Earnings Per Share [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xml:lang="en-US"> Earnings per share, basic and diluted: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerBasicAndDilutedShare" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicAndDilutedShare"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicAndDilutedShare_lbl" xml:lang="en-US"> Income (Loss) from Continuing Operations, Per Basic and Diluted Share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicAndDilutedShare_lbl" xml:lang="en-US"> From continuing operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsPerBasicAndDilutedShare_lbl" xml:lang="en-US"> Earnings from continuing operations per share, basic and diluted </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare" xlink:to="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare_lbl" xml:lang="en-US"> Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic and Diluted Share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare_lbl" xml:lang="en-US"> From discontinued operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare_lbl" xml:lang="en-US"> Earnings (loss) from discontinued operations per share, net of tax, basic and diluted </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasicAndDiluted" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted_lbl" xml:lang="en-US"> Earnings Per Share, Basic and Diluted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted_lbl" xml:lang="en-US"> Net earnings per share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl" xml:lang="en-US"> Statement of Other Comprehensive Income [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl" xml:lang="en-US"> Comprehensive income: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_lbl" xml:lang="en-US"> Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_lbl" xml:lang="en-US"> Other comprehensive income (loss), net of tax: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:to="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_lbl" xml:lang="en-US"> Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_lbl" xml:lang="en-US"> Unrealized gain (loss) on available-for-sale securities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_lbl" xml:lang="en-US"> Unrealized gain (loss) on available-for-sale securities, net of tax </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xml:lang="en-US"> Comprehensive Income (Loss), Net of Tax, Attributable to Parent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xml:lang="en-US"> Comprehensive income </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US"> Consolidated Statements Of Cash Flows [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Cash flows from operating activities: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Adjustments to reconcile net earnings to net cash provided by operating activities, net of acquisition related assets: </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US"> Adjustments to reconcile net earnings to net cash provided by operating activities: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Depreciation_lbl" xml:lang="en-US"> Provision for depreciation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Deferred income tax expense benefit </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Deferred income tax (benefit) </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNoncashIncomeTaxExpense" xlink:label="us-gaap_OtherNoncashIncomeTaxExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNoncashIncomeTaxExpense" xlink:to="us-gaap_OtherNoncashIncomeTaxExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNoncashIncomeTaxExpense_lbl" xml:lang="en-US"> Other Noncash Income Tax Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherNoncashIncomeTaxExpense_lbl" xml:lang="en-US"> Noncash income tax expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax" xlink:label="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax" xlink:to="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Net loss (gain) and impairment on divestiture of businesses from discontinued operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Gain on divestiture, net </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_GainOnInvoluntaryConversionOfMachineryAndEquipment" xlink:label="npk_GainOnInvoluntaryConversionOfMachineryAndEquipment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_GainOnInvoluntaryConversionOfMachineryAndEquipment" xlink:to="npk_GainOnInvoluntaryConversionOfMachineryAndEquipment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_GainOnInvoluntaryConversionOfMachineryAndEquipment_lbl" xml:lang="en-US"> Gain on involuntary converstion of machinery and equipment. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_GainOnInvoluntaryConversionOfMachineryAndEquipment_lbl" xml:lang="en-US"> Gain on Involuntary Conversion of Machinery and Equipment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="npk_GainOnInvoluntaryConversionOfMachineryAndEquipment_lbl" xml:lang="en-US"> Net gain on involuntary conversion of machinery and equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:to="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xml:lang="en-US"> Impairment of Long-Lived Assets Held-for-use </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xml:lang="en-US"> Impairment of long-lived assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xml:lang="en-US"> Impairment of Property, Plant and Equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges" xlink:label="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges" xlink:to="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_lbl" xml:lang="en-US"> Loss (gain) on disposal and impairment of property, plant and equipment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_lbl" xml:lang="en-US"> Loss on disposal and impairment of property, plant and equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="us-gaap_ProvisionForDoubtfulAccounts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProvisionForDoubtfulAccounts" xlink:to="us-gaap_ProvisionForDoubtfulAccounts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl" xml:lang="en-US"> Provision for Doubtful Accounts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl" xml:lang="en-US"> Provision for doubtful accounts </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_NoncashRetirementPlanExpense" xlink:label="npk_NoncashRetirementPlanExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_NoncashRetirementPlanExpense" xlink:to="npk_NoncashRetirementPlanExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_NoncashRetirementPlanExpense_lbl" xml:lang="en-US"> Noncash retirement plan expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_NoncashRetirementPlanExpense_lbl" xml:lang="en-US"> Noncash retirement plan expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_NoncashRetirementPlanExpense_lbl" xml:lang="en-US"> Non-cash retirement plan expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossRelatedToLitigationSettlement" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement_lbl" xml:lang="en-US"> Gain (Loss) Related to Litigation Settlement </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement_lbl" xml:lang="en-US"> Gain on legal settlement </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="us-gaap_OtherNoncashIncomeExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNoncashIncomeExpense" xlink:to="us-gaap_OtherNoncashIncomeExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xml:lang="en-US"> Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xml:lang="en-US"> Other </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xml:lang="en-US"> Changes in: </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xml:lang="en-US"> Changes in operating accounts, net of effects of acquisition: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xml:lang="en-US"> Accounts receivable </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xml:lang="en-US"> Accounts receivable, net </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="us-gaap_IncreaseDecreaseInInventories"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInventories" xlink:to="us-gaap_IncreaseDecreaseInInventories_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl" xml:lang="en-US"> Inventories </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl" xml:lang="en-US"> Inventories </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US"> Other assets and current assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xml:lang="en-US"> Other assets and current assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US"> Accounts payable and accrued liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable" xlink:label="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable" xlink:to="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable_lbl" xml:lang="en-US"> Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable_lbl" xml:lang="en-US"> Federal and state income taxes receivable/payable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Operating Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US"> Net cash provided by operating activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US"> Cash flows from investing activities: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:to="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl" xml:lang="en-US"> Marketable securities purchased </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl" xml:lang="en-US"> Marketable securities purchased </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_lbl" xml:lang="en-US"> Proceeds from sale and maturity of available for sale securities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_lbl" xml:lang="en-US"> Marketable securities - maturities and sales </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested" xlink:label="us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested" xlink:to="us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_lbl" xml:lang="en-US"> Proceeds from Divestiture of Businesses, Net of Cash Paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_lbl" xml:lang="en-US"> Proceeds from divestiture of businesses, net of cash paid </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Acquisition of property, plant and equipment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US"> Purchase of property, plant and equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireNotesReceivable" xlink:label="us-gaap_PaymentsToAcquireNotesReceivable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireNotesReceivable" xlink:to="us-gaap_PaymentsToAcquireNotesReceivable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireNotesReceivable_lbl" xml:lang="en-US"> Notes Issued </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireNotesReceivable_lbl" xml:lang="en-US"> Notes issued </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable" xlink:label="us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable" xlink:to="us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable_lbl" xml:lang="en-US"> Proceeds from Sale and Collection of Notes Receivable </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleAndCollectionOfNotesReceivable_lbl" xml:lang="en-US"> Proceeds from note receivable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xml:lang="en-US"> Business Acquisition, Cost of Acquired Entity, Cash Paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xml:lang="en-US"> Acquisition of business, net of cash acquired </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ProceedsFromLegalSettlementsInvestingActivities" xlink:label="npk_ProceedsFromLegalSettlementsInvestingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ProceedsFromLegalSettlementsInvestingActivities" xlink:to="npk_ProceedsFromLegalSettlementsInvestingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ProceedsFromLegalSettlementsInvestingActivities_lbl" xml:lang="en-US"> Proceeds from Legal Settlements, Investing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ProceedsFromLegalSettlementsInvestingActivities_lbl" xml:lang="en-US"> Proceeds from Legal Settlements, Investing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_ProceedsFromLegalSettlementsInvestingActivities_lbl" xml:lang="en-US"> Proceeds from legal settlement </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:label="us-gaap_ProceedsFromInsuranceSettlementInvestingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromInsuranceSettlementInvestingActivities" xlink:to="us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_lbl" xml:lang="en-US"> Proceeds from Insurance Settlement, Investing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromInsuranceSettlementInvestingActivities_lbl" xml:lang="en-US"> Proceeds from insurance settlement </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireIntangibleAssets" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireIntangibleAssets" xlink:to="us-gaap_PaymentsToAcquireIntangibleAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets_lbl" xml:lang="en-US"> Acquisition of intangible assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets_lbl" xml:lang="en-US"> Acquisition of intangible assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Sale of property, plant and equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Investing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US"> Net cash provided by (used in) investing activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US"> Cash flows from financing activities: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsOfDividendsCommonStock" xlink:label="us-gaap_PaymentsOfDividendsCommonStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDividendsCommonStock" xlink:to="us-gaap_PaymentsOfDividendsCommonStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xml:lang="en-US"> Dividends paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xml:lang="en-US"> Dividends paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xml:lang="en-US"> Dividends paid on common stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleOfTreasuryStock" xlink:label="us-gaap_ProceedsFromSaleOfTreasuryStock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfTreasuryStock" xlink:to="us-gaap_ProceedsFromSaleOfTreasuryStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleOfTreasuryStock_lbl" xml:lang="en-US"> Proceeds from Sale of Treasury Stock </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleOfTreasuryStock_lbl" xml:lang="en-US"> Proceeds from sale of treasury stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl" xml:lang="en-US"> Proceeds From Payments For Other Financing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl" xml:lang="en-US"> Other </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US"> Net Cash Provided by (Used in) Financing Activities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US"> Net cash used in financing activities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl" xml:lang="en-US"> Cash and Cash Equivalents, Period Increase (Decrease) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl" xml:lang="en-US"> Net increase (decrease) in cash and cash equivalents </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xml:lang="en-US"> Cash and cash equivalents at end of year </label>
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<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xml:lang="en-US"> Supplemental disclosures of cash flow information: </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxesPaid" xlink:label="us-gaap_IncomeTaxesPaid"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxesPaid_lbl" xml:lang="en-US"> Income Taxes Paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxesPaid_lbl" xml:lang="en-US"> Income taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xml:lang="en-US"> Statement of Stockholders' Equity [Abstract] </label>
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<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsCommonStock" xlink:to="us-gaap_DividendsCommonStock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsCommonStock_lbl" xml:lang="en-US"> Dividends, Common Stock </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DividendsCommonStock_lbl" xml:lang="en-US"> Dividends paid </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityOther" xlink:label="us-gaap_StockholdersEquityOther"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityOther" xlink:to="us-gaap_StockholdersEquityOther_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityOther_lbl" xml:lang="en-US"> Stockholders' Equity, Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockholdersEquityOther_lbl" xml:lang="en-US"> Other </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityOtherShares" xlink:label="us-gaap_StockholdersEquityOtherShares"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityOtherShares" xlink:to="us-gaap_StockholdersEquityOtherShares_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityOtherShares_lbl" xml:lang="en-US"> Stockholders' Equity, Other Shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockholdersEquityOtherShares_lbl" xml:lang="en-US"> Other, shares </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_RegularDividendsPerSharePaid" xlink:label="npk_RegularDividendsPerSharePaid"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_RegularDividendsPerSharePaid" xlink:to="npk_RegularDividendsPerSharePaid_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_RegularDividendsPerSharePaid_lbl" xml:lang="en-US"> Regular dividends per share paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_RegularDividendsPerSharePaid_lbl" xml:lang="en-US"> Regular dividends per share paid </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ExtraDividendsPerSharePaid" xlink:label="npk_ExtraDividendsPerSharePaid"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ExtraDividendsPerSharePaid" xlink:to="npk_ExtraDividendsPerSharePaid_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ExtraDividendsPerSharePaid_lbl" xml:lang="en-US"> Extra dividends per share paid </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ExtraDividendsPerSharePaid_lbl" xml:lang="en-US"> Extra dividends per share paid </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xml:lang="en-US"> Summary Of Significant Accounting Policies [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US"> Significant Accounting Policies [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US"> Summary Of Significant Accounting Policies </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="us-gaap_InventoryDisclosureAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureAbstract" xlink:to="us-gaap_InventoryDisclosureAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xml:lang="en-US"> Inventories [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="us-gaap_InventoryDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xml:lang="en-US"> Inventory Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xml:lang="en-US"> Inventories </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrentAbstract" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrentAbstract"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrentAndNoncurrentAbstract_lbl" xml:lang="en-US"> Accrued Liabilities [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_lbl" xml:lang="en-US"> Accounts Payable and Accrued Liabilities Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_lbl" xml:lang="en-US"> Accrued Liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TreasuryStockNumberOfSharesAndRestrictionDisclosuresAbstract" xlink:label="us-gaap_TreasuryStockNumberOfSharesAndRestrictionDisclosuresAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockNumberOfSharesAndRestrictionDisclosuresAbstract" xlink:to="us-gaap_TreasuryStockNumberOfSharesAndRestrictionDisclosuresAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockNumberOfSharesAndRestrictionDisclosuresAbstract_lbl" xml:lang="en-US"> Treasury Stock [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TreasuryStockTextBlock" xlink:label="us-gaap_TreasuryStockTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockTextBlock" xlink:to="us-gaap_TreasuryStockTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockTextBlock_lbl" xml:lang="en-US"> Treasury Stock [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_TreasuryStockTextBlock_lbl" xml:lang="en-US"> Treasury Stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="us-gaap_EarningsPerShareTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareTextBlock" xlink:to="us-gaap_EarningsPerShareTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xml:lang="en-US"> Earnings Per Share Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xml:lang="en-US"> Net Earnings Per Share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationAbstract" xlink:label="us-gaap_ShareBasedCompensationAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationAbstract" xlink:to="us-gaap_ShareBasedCompensationAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationAbstract_lbl" xml:lang="en-US"> Stock-Based Compensation [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xml:lang="en-US"> Disclosure of Compensation Related Costs, Share-based Payments [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xml:lang="en-US"> Stock-Based Compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:label="us-gaap_CompensationAndRetirementDisclosureAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:to="us-gaap_CompensationAndRetirementDisclosureAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CompensationAndRetirementDisclosureAbstract_lbl" xml:lang="en-US"> 401(k) Plan [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:to="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl" xml:lang="en-US"> Pension and Other Postretirement Benefits Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl" xml:lang="en-US"> 401(k) Plan </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xml:lang="en-US"> Income Taxes [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US"> Income Tax Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US"> Income Taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xml:lang="en-US"> Commitments And Contingencies [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US"> Commitments And Contingencies Disclosure Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US"> Commitments And Contingencies </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ConcentrationsAbstract" xlink:label="npk_ConcentrationsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ConcentrationsAbstract" xlink:to="npk_ConcentrationsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ConcentrationsAbstract_lbl" xml:lang="en-US"> Concentrations [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ConcentrationsAbstract_lbl" xml:lang="en-US"> Concentrations [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:label="us-gaap_ConcentrationRiskDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskDisclosureTextBlock" xlink:to="us-gaap_ConcentrationRiskDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskDisclosureTextBlock_lbl" xml:lang="en-US"> Concentration Risk Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ConcentrationRiskDisclosureTextBlock_lbl" xml:lang="en-US"> Concentrations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalExpenseAndLiabilitiesAbstract" xlink:label="us-gaap_EnvironmentalExpenseAndLiabilitiesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EnvironmentalExpenseAndLiabilitiesAbstract" xlink:to="us-gaap_EnvironmentalExpenseAndLiabilitiesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EnvironmentalExpenseAndLiabilitiesAbstract_lbl" xml:lang="en-US"> Environmental [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EnvironmentalLossContingencyDisclosureTextBlock" xlink:label="us-gaap_EnvironmentalLossContingencyDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EnvironmentalLossContingencyDisclosureTextBlock" xlink:to="us-gaap_EnvironmentalLossContingencyDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EnvironmentalLossContingencyDisclosureTextBlock_lbl" xml:lang="en-US"> Environmental Loss Contingency Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EnvironmentalLossContingencyDisclosureTextBlock_lbl" xml:lang="en-US"> Environmental </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xml:lang="en-US"> Business Segments [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US"> Segment Reporting Disclosure Text Block </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US"> Business Segments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LeasesAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeasesAbstract_lbl" xml:lang="en-US"> Leases [Abstract] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_Leases" xlink:label="npk_Leases"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_Leases" xlink:to="npk_Leases_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_Leases_lbl" xml:lang="en-US"> The entire disclosure for the entity's leasing activities as lessee and lessor. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_Leases_lbl" xml:lang="en-US"> Leases </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_Leases_lbl" xml:lang="en-US"> Leases </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_QuarterlyFinancialDataAbstract" xlink:label="us-gaap_QuarterlyFinancialDataAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialDataAbstract" xlink:to="us-gaap_QuarterlyFinancialDataAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_QuarterlyFinancialDataAbstract_lbl" xml:lang="en-US"> Interim Financial Information [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_QuarterlyFinancialInformationTextBlock" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialInformationTextBlock" xlink:to="us-gaap_QuarterlyFinancialInformationTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock_lbl" xml:lang="en-US"> Quarterly Financial Information [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock_lbl" xml:lang="en-US"> Interim Financial Information </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityAbstract" xlink:label="us-gaap_LineOfCreditFacilityAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAbstract" xlink:to="us-gaap_LineOfCreditFacilityAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityAbstract_lbl" xml:lang="en-US"> Line of Credit And Commercial Letters Of Credit [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShortTermDebtTextBlock" xlink:label="us-gaap_ShortTermDebtTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTextBlock" xlink:to="us-gaap_ShortTermDebtTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermDebtTextBlock_lbl" xml:lang="en-US"> Short-term Debt [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShortTermDebtTextBlock_lbl" xml:lang="en-US"> Line Of Credit And Commercial Letters Of Credit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract" xlink:label="us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract" xlink:to="us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract_lbl" xml:lang="en-US"> Discontinued Operations [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock" xlink:to="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock_lbl" xml:lang="en-US"> Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock_lbl" xml:lang="en-US"> Discontinued Operations </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DivestitureAbstract" xlink:label="npk_DivestitureAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DivestitureAbstract" xlink:to="npk_DivestitureAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DivestitureAbstract_lbl" xml:lang="en-US"> Divstiture abstract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DivestitureAbstract_lbl" xml:lang="en-US"> Divestiture [Abstract] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DivestitureTextBlock" xlink:label="npk_DivestitureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DivestitureTextBlock" xlink:to="npk_DivestitureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DivestitureTextBlock_lbl" xml:lang="en-US"> Entire disclosure for divestiture </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DivestitureTextBlock_lbl" xml:lang="en-US"> Divestiture [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_DivestitureTextBlock_lbl" xml:lang="en-US"> Divestiture </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationsAbstract_lbl" xml:lang="en-US"> Business Acquisition [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationDisclosureTextBlock" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xml:lang="en-US"> Business Combination Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xml:lang="en-US"> Business Acquisition </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_OtherAbstract" xlink:label="npk_OtherAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_OtherAbstract" xlink:to="npk_OtherAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_OtherAbstract_lbl" xml:lang="en-US"> Other [Abstract] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_OtherAbstract_lbl" xml:lang="en-US"> Other [Abstract] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_OtherDisclosureTextBlock" xlink:label="npk_OtherDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_OtherDisclosureTextBlock" xlink:to="npk_OtherDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_OtherDisclosureTextBlock_lbl" xml:lang="en-US"> Other Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_OtherDisclosureTextBlock_lbl" xml:lang="en-US"> Other Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_OtherDisclosureTextBlock_lbl" xml:lang="en-US"> Other </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xml:lang="en-US"> Subsequent Event [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US"> Subsequent Events [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US"> Subsequent Event </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ValuationAndQualifyingAccountsAbstract" xlink:label="srt_ValuationAndQualifyingAccountsAbstract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ValuationAndQualifyingAccountsAbstract" xlink:to="srt_ValuationAndQualifyingAccountsAbstract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ValuationAndQualifyingAccountsAbstract_lbl" xml:lang="en-US"> Schedule II - Valuation and Qualifying Accounts [Abstract] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:label="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:to="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_lbl" xml:lang="en-US"> Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_lbl" xml:lang="en-US"> Schedule II - Valuation And Qualifying Accounts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US"> Use of Estimates, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US"> Use Of Estimates In The Preparation Of Financial Statements </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:label="us-gaap_ConsolidationPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConsolidationPolicyTextBlock" xlink:to="us-gaap_ConsolidationPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xml:lang="en-US"> Consolidation, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xml:lang="en-US"> Basis Of Presentation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="us-gaap_PriorPeriodReclassificationAdjustmentDescription_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription_lbl" xml:lang="en-US"> Reclassification, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription_lbl" xml:lang="en-US"> Reclassifications </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:to="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl" xml:lang="en-US"> Fair Value of Financial Instruments, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl" xml:lang="en-US"> Fair Value Of Financial Instruments </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock" xlink:label="npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock" xlink:to="npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock_lbl" xml:lang="en-US"> Cash Cash Equivalents And Marketable Securities [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock_lbl" xml:lang="en-US"> Cash Cash Equivalents And Marketable Securities [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_CashCashEquivalentsAndMarketableSecuritiesPolicyTextBlock_lbl" xml:lang="en-US"> Cash Cash Equivalents And Marketable Securities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ReceivablesPolicyTextBlock" xlink:label="us-gaap_ReceivablesPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReceivablesPolicyTextBlock" xlink:to="us-gaap_ReceivablesPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ReceivablesPolicyTextBlock_lbl" xml:lang="en-US"> Receivables, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ReceivablesPolicyTextBlock_lbl" xml:lang="en-US"> Accounts Receivable </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="us-gaap_InventoryPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryPolicyTextBlock" xlink:to="us-gaap_InventoryPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xml:lang="en-US"> Inventory, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xml:lang="en-US"> Inventories </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US"> Property, Plant and Equipment, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US"> Property, Plant And Equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:to="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xml:lang="en-US"> Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xml:lang="en-US"> Goodwill </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsFiniteLivedPolicy" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsFiniteLivedPolicy" xlink:to="us-gaap_IntangibleAssetsFiniteLivedPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy_lbl" xml:lang="en-US"> Intangible Assets, Finite-Lived, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy_lbl" xml:lang="en-US"> Intangible Assets </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_OtherAssetsPolicy" xlink:label="npk_OtherAssetsPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_OtherAssetsPolicy" xlink:to="npk_OtherAssetsPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_OtherAssetsPolicy_lbl" xml:lang="en-US"> Policy for other assets not otherwise classified. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_OtherAssetsPolicy_lbl" xml:lang="en-US"> Other Assets Policy </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_OtherAssetsPolicy_lbl" xml:lang="en-US"> Other Assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock" xlink:to="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl" xml:lang="en-US"> Revenue from Contract with Customer [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RevenueFromContractWithCustomerPolicyTextBlock_lbl" xml:lang="en-US"> Revenues </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdvertisingCostsPolicyTextBlock" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdvertisingCostsPolicyTextBlock" xlink:to="us-gaap_AdvertisingCostsPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock_lbl" xml:lang="en-US"> Advertising Costs, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock_lbl" xml:lang="en-US"> Advertising </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StandardProductWarrantyPolicy" xlink:label="us-gaap_StandardProductWarrantyPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StandardProductWarrantyPolicy" xlink:to="us-gaap_StandardProductWarrantyPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StandardProductWarrantyPolicy_lbl" xml:lang="en-US"> Standard Product Warranty, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StandardProductWarrantyPolicy_lbl" xml:lang="en-US"> Product Warranty </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US"> Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US"> Stock-Based Compensation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US"> Income Tax, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xml:lang="en-US"> Income Taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US"> New Accounting Pronouncements, Policy [Policy Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US"> Recently Issued Accounting Pronouncements </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Available-for-sale Securities Reconciliation [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock_lbl" xml:lang="en-US"> Summary Of The Amortized Costs And Fair Values Of Marketable Securities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock" xlink:label="us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock" xlink:to="us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock_lbl" xml:lang="en-US"> Schedule of Product Warranty Liability [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfProductWarrantyLiabilityTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Changes In Product Warranty </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock" xlink:label="npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock" xlink:to="npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Potential Impact Of LIFO Valuation to FIFO Valuation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Potential Impact Of L I F O Valuation to F I F O Valuation [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_ScheduleOfPotentialImpactOfLIFOValuationToFIFOValuationTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Potential Impact Of LIFO Valuation to FIFO Valuation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock_lbl" xml:lang="en-US"> Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Activity For Non-Vested Restricted Stock </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl" xml:lang="en-US"> Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Provision For Income Taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US"> Reconciliation Of Statutory Rate to Effective Rate </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule of Deferred Tax Assets and Liabilities [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Deferred Tax Assets And Liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:to="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl" xml:lang="en-US"> Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl" xml:lang="en-US"> Reconciliation Of Unrecognized Tax Benefits </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock" xlink:label="npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock" xlink:to="npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Expected Future Payments Of Environmental Matters </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Expected Future Payments Of Environmental Matters [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_ScheduleOfExpectedFuturePaymentsOfEnvironmentalMattersTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Expected Future Payments Of Environmental Matters </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xml:lang="en-US"> Schedule of Segment Reporting Information, by Segment [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xml:lang="en-US"> Summary Of Business Segment Information </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LeaseCostTableTextBlock" xlink:label="us-gaap_LeaseCostTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostTableTextBlock" xlink:to="us-gaap_LeaseCostTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xml:lang="en-US"> Lease, Cost [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xml:lang="en-US"> Summary of Lease Cost </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_lbl" xml:lang="en-US"> Lessee, Operating Lease, Liability, Maturity [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_lbl" xml:lang="en-US"> Summary of Operating Lease Liability Maturities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLeaseIncomeTableTextBlock" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock" xlink:to="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock_lbl" xml:lang="en-US"> Operating Lease, Lease Income [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock_lbl" xml:lang="en-US"> Summary of Lease Income from Operating Lease Payments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:to="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl" xml:lang="en-US"> Schedule of Quarterly Financial Information [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Quarterly Financial Information </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:to="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" xml:lang="en-US"> Disposal Groups, Including Discontinued Operations [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" xml:lang="en-US"> Results Of Discontinued Operations And Schedule Of Major Classes Of Assets And Liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:to="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl" xml:lang="en-US"> Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl" xml:lang="en-US"> Schedule Of Assets Acquired and Liabilities Assumed </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:to="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl" xml:lang="en-US"> Business Acquisition, Pro Forma Information [Table Text Block] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl" xml:lang="en-US"> Schedule Of Pro Forma Results of Operations </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_SignificantAccountingPoliciesTable" xlink:label="npk_SignificantAccountingPoliciesTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_SignificantAccountingPoliciesTable" xlink:to="npk_SignificantAccountingPoliciesTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_SignificantAccountingPoliciesTable_lbl" xml:lang="en-US"> Significant Accounting Policies [Table] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_SignificantAccountingPoliciesTable_lbl" xml:lang="en-US"> Significant Accounting Policies [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RangeAxis_lbl" xml:lang="en-US"> Range [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeMember" xlink:to="srt_RangeMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RangeMember_lbl" xml:lang="en-US"> Range [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_RangeMember_lbl" xml:lang="en-US"> Range [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MinimumMember_lbl" xml:lang="en-US"> Minimum [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_MinimumMember_lbl" xml:lang="en-US"> Minimum [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MaximumMember_lbl" xml:lang="en-US"> Maximum [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_MaximumMember_lbl" xml:lang="en-US"> Maximum [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_FinancialInstrumentAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xml:lang="en-US"> Financial Instrument [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xml:lang="en-US"> Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xml:lang="en-US"> Major Types of Debt and Equity Securities [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableRateDemandObligationMember" xlink:label="us-gaap_VariableRateDemandObligationMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableRateDemandObligationMember" xlink:to="us-gaap_VariableRateDemandObligationMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_VariableRateDemandObligationMember_lbl" xml:lang="en-US"> Variable Rate Demand Obligation [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_VariableRateDemandObligationMember_lbl" xml:lang="en-US"> Variable Rate Demand Notes [Member] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_SignificantAccountingPoliciesLineItems" xlink:label="npk_SignificantAccountingPoliciesLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_SignificantAccountingPoliciesLineItems" xlink:to="npk_SignificantAccountingPoliciesLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_SignificantAccountingPoliciesLineItems_lbl" xml:lang="en-US"> Significant Accounting Policies [Line Items] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_SignificantAccountingPoliciesLineItems_lbl" xml:lang="en-US"> Significant Accounting Policies [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:label="us-gaap_ProceedsFromDivestitureOfBusinesses"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:to="us-gaap_ProceedsFromDivestitureOfBusinesses_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromDivestitureOfBusinesses_lbl" xml:lang="en-US"> Proceeds from Divestiture of Businesses </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromDivestitureOfBusinesses_lbl" xml:lang="en-US"> Proceeds from sale </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsPayableOtherCurrent" xlink:label="us-gaap_AccountsPayableOtherCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableOtherCurrent" xlink:to="us-gaap_AccountsPayableOtherCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableOtherCurrent_lbl" xml:lang="en-US"> Other Restricted Assets, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsPayableOtherCurrent_lbl" xml:lang="en-US"> Checks outstanding </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet" xlink:label="us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet" xlink:to="us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet_lbl" xml:lang="en-US"> Available-for-sale Securities, Gross Realized Gain (Loss) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet_lbl" xml:lang="en-US"> Gross gains or losses related to sales of marketable securities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax_lbl" xml:lang="en-US"> Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax_lbl" xml:lang="en-US"> Net unrealized gains (losses) included OCI </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_lbl" xml:lang="en-US"> Available-for-sale Securities, Debt Maturities, within One Year, Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_lbl" xml:lang="en-US"> Contractual maturities of marketable securities, within one year </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_lbl" xml:lang="en-US"> Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_lbl" xml:lang="en-US"> Contractual maturities of marketable securities, beyond one year to five years </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_lbl" xml:lang="en-US"> Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_lbl" xml:lang="en-US"> Contractual maturities of marketable securities, beyond five years to ten years </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_lbl" xml:lang="en-US"> Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_lbl" xml:lang="en-US"> Contractual maturities of marketable securities, beyond ten years </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_NumberOfDaysToTenderSecurites" xlink:label="npk_NumberOfDaysToTenderSecurites"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_NumberOfDaysToTenderSecurites" xlink:to="npk_NumberOfDaysToTenderSecurites_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_NumberOfDaysToTenderSecurites_lbl" xml:lang="en-US"> Number of days to tender securites </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_NumberOfDaysToTenderSecurites_lbl" xml:lang="en-US"> Number of days to tender securites </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_AccountsReceivableCollectionPeriod" xlink:label="npk_AccountsReceivableCollectionPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_AccountsReceivableCollectionPeriod" xlink:to="npk_AccountsReceivableCollectionPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_AccountsReceivableCollectionPeriod_lbl" xml:lang="en-US"> Accounts receivable, collection period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_AccountsReceivableCollectionPeriod_lbl" xml:lang="en-US"> Accounts receivable, collection period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xml:lang="en-US"> Property, Plant and Equipment, Useful Life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xml:lang="en-US"> Useful life </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConstructionInProgressGross" xlink:label="us-gaap_ConstructionInProgressGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionInProgressGross" xlink:to="us-gaap_ConstructionInProgressGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xml:lang="en-US"> Construction in Progress, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xml:lang="en-US"> Construction in progress </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="us-gaap_GoodwillImpairmentLoss"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillImpairmentLoss" xlink:to="us-gaap_GoodwillImpairmentLoss_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xml:lang="en-US"> Goodwill impairment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xml:lang="en-US"> Goodwill impairment charges </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss" xlink:to="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_lbl" xml:lang="en-US"> Goodwill, Impaired, Accumulated Impairment Loss </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_lbl" xml:lang="en-US"> Goodwill, Cumulative Impairment Charges </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xml:lang="en-US"> Finite-Lived Intangible Asset, Useful Life </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xml:lang="en-US"> Economic use period for intangibles </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_lbl" xml:lang="en-US"> Impairment of Intangible Assets (Excluding Goodwill) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_lbl" xml:lang="en-US"> Impairments of Intangible Assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US"> Gross carrying amount of intangibles </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US"> Finite-Lived Intangible Assets, Accumulated Amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US"> Accumulated amortization of intangibles </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ExpectedPrepaymentUtilizationPeriod" xlink:label="npk_ExpectedPrepaymentUtilizationPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ExpectedPrepaymentUtilizationPeriod" xlink:to="npk_ExpectedPrepaymentUtilizationPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ExpectedPrepaymentUtilizationPeriod_lbl" xml:lang="en-US"> Expected prepayment utilization period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ExpectedPrepaymentUtilizationPeriod_lbl" xml:lang="en-US"> Expected prepayment utilization period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MaterialsSuppliesAndOther" xlink:label="us-gaap_MaterialsSuppliesAndOther"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MaterialsSuppliesAndOther" xlink:to="us-gaap_MaterialsSuppliesAndOther_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MaterialsSuppliesAndOther_lbl" xml:lang="en-US"> Materials, Supplies, and Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MaterialsSuppliesAndOther_lbl" xml:lang="en-US"> Materials Prepayments </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_HoldingPeriodFollowingRecognitionOfRevenue" xlink:label="npk_HoldingPeriodFollowingRecognitionOfRevenue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_HoldingPeriodFollowingRecognitionOfRevenue" xlink:to="npk_HoldingPeriodFollowingRecognitionOfRevenue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_HoldingPeriodFollowingRecognitionOfRevenue_lbl" xml:lang="en-US"> Holding period following recognition of revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_HoldingPeriodFollowingRecognitionOfRevenue_lbl" xml:lang="en-US"> Holding period following recognition of revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_HoldingPeriodFollowingRecognitionOfRevenue_lbl" xml:lang="en-US"> Holding period following recognition of revenue </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" xml:lang="en-US"> Contract with Customer, Liability, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" xml:lang="en-US"> Contract liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xml:lang="en-US"> Contract with Customer, Liability, Revenue Recognized </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xml:lang="en-US"> Revenue recognized that was previously included in contract liability </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice" xlink:label="us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice" xlink:to="us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_lbl" xml:lang="en-US"> Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_lbl" xml:lang="en-US"> Change in estimate of variable consideration </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_RevenueFromContractWithCustomerContractTerm" xlink:label="npk_RevenueFromContractWithCustomerContractTerm"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_RevenueFromContractWithCustomerContractTerm" xlink:to="npk_RevenueFromContractWithCustomerContractTerm_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_RevenueFromContractWithCustomerContractTerm_lbl" xml:lang="en-US"> Revenue from contract with customer, contract term </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_RevenueFromContractWithCustomerContractTerm_lbl" xml:lang="en-US"> Revenue from contract with customer, contract term </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_RevenueFromContractWithCustomerContractTerm_lbl" xml:lang="en-US"> Contract term </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod" xlink:label="us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod" xlink:to="us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_lbl" xml:lang="en-US"> Contract with Customer, Performance Obligation Satisfied in Previous Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_lbl" xml:lang="en-US"> Revenue recognized from performance obligations satisfied in a prior period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="us-gaap_RevenueRemainingPerformanceObligation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligation" xlink:to="us-gaap_RevenueRemainingPerformanceObligation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xml:lang="en-US"> Revenue, Remaining Performance Obligation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xml:lang="en-US"> Unsatified performance obligations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl" xml:lang="en-US"> Fulfullment period of unsatisfied performance obligations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_lbl" xml:lang="en-US"> Fulfillment period of unsatisfied performance obligations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="us-gaap_NumberOfReportableSegments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US"> Number of Reportable Segments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US"> Number of reportable segments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdvertisingExpense" xlink:label="us-gaap_AdvertisingExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdvertisingExpense" xlink:to="us-gaap_AdvertisingExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdvertisingExpense_lbl" xml:lang="en-US"> Advertising expense </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_StandardProductWarrantyCoveragePeriod" xlink:label="npk_StandardProductWarrantyCoveragePeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_StandardProductWarrantyCoveragePeriod" xlink:to="npk_StandardProductWarrantyCoveragePeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_StandardProductWarrantyCoveragePeriod_lbl" xml:lang="en-US"> Standard product warranty coverage period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_StandardProductWarrantyCoveragePeriod_lbl" xml:lang="en-US"> Standard product warranty coverage period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_lbl" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="us-gaap_StatementBusinessSegmentsAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementBusinessSegmentsAxis" xlink:to="us-gaap_StatementBusinessSegmentsAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xml:lang="en-US"> Business Segments [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="us-gaap_SegmentDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_SegmentDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentDomain_lbl" xml:lang="en-US"> Segment [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentDomain_lbl" xml:lang="en-US"> Segment [Domain] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DefenseProductsMember" xlink:label="npk_DefenseProductsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DefenseProductsMember" xlink:to="npk_DefenseProductsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DefenseProductsMember_lbl" xml:lang="en-US"> Defense products. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DefenseProductsMember_lbl" xml:lang="en-US"> Defense Products [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_DefenseProductsMember_lbl" xml:lang="en-US"> Defense [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_lbl" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:to="us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_lbl" xml:lang="en-US"> Schedule of Available-for-sale Securities [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NontaxableMunicipalBondsMember" xlink:label="us-gaap_NontaxableMunicipalBondsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NontaxableMunicipalBondsMember" xlink:to="us-gaap_NontaxableMunicipalBondsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NontaxableMunicipalBondsMember_lbl" xml:lang="en-US"> Nontaxable Municipal Bonds [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NontaxableMunicipalBondsMember_lbl" xml:lang="en-US"> Tax-Exempt Municipal Bonds [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_lbl" xml:lang="en-US"> Schedule of Available-for-sale Securities [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xml:lang="en-US"> Available-for-sale Debt Securities, Amortized Cost Basis </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xml:lang="en-US"> MARKETABLE SECURITIES, Amortized Cost </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl" xml:lang="en-US"> Available-for-sale Securities, Debt Securities, Current </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl" xml:lang="en-US"> MARKETABLE SECURITIES, Fair Value </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl" xml:lang="en-US"> Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl" xml:lang="en-US"> MARKETABLE SECURITIES, Gross Unrealized Gains </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xml:lang="en-US"> Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xml:lang="en-US"> MARKETABLE SECURITIES, Gross Unrealized Losses </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StandardProductWarrantyAccrual" xlink:label="us-gaap_StandardProductWarrantyAccrual"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StandardProductWarrantyAccrual" xlink:to="us-gaap_StandardProductWarrantyAccrual_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StandardProductWarrantyAccrual_lbl" xml:lang="en-US"> Standard Product Warranty Accrual </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StandardProductWarrantyAccrual_lbl" xml:lang="en-US"> Balance December 31 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StandardProductWarrantyAccrual_lbl" xml:lang="en-US"> Beginning balance January 1 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StandardProductWarrantyAccrualWarrantiesIssued" xlink:label="us-gaap_StandardProductWarrantyAccrualWarrantiesIssued"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StandardProductWarrantyAccrualWarrantiesIssued" xlink:to="us-gaap_StandardProductWarrantyAccrualWarrantiesIssued_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StandardProductWarrantyAccrualWarrantiesIssued_lbl" xml:lang="en-US"> Standard Product Warranty Accrual, Warranties Issued </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StandardProductWarrantyAccrualWarrantiesIssued_lbl" xml:lang="en-US"> Accruals during the period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StandardProductWarrantyAccrualPayments" xlink:label="us-gaap_StandardProductWarrantyAccrualPayments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StandardProductWarrantyAccrualPayments" xlink:to="us-gaap_StandardProductWarrantyAccrualPayments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StandardProductWarrantyAccrualPayments_lbl" xml:lang="en-US"> Standard Product Warranty Accrual, Payments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_StandardProductWarrantyAccrualPayments_lbl" xml:lang="en-US"> Charges / payments made under the warranties </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryCurrentTable" xlink:label="us-gaap_InventoryCurrentTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryCurrentTable" xlink:to="us-gaap_InventoryCurrentTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryCurrentTable_lbl" xml:lang="en-US"> Inventory, Current [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryLineItems" xlink:label="us-gaap_InventoryLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryLineItems" xlink:to="us-gaap_InventoryLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryLineItems_lbl" xml:lang="en-US"> Inventory [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LIFOInventoryAmount" xlink:label="us-gaap_LIFOInventoryAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LIFOInventoryAmount" xlink:to="us-gaap_LIFOInventoryAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LIFOInventoryAmount_lbl" xml:lang="en-US"> LIFO Inventory Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LIFOInventoryAmount_lbl" xml:lang="en-US"> LIFO inventory amount </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue" xlink:label="us-gaap_ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue" xlink:to="us-gaap_ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue_lbl" xml:lang="en-US"> Inventory valuation, difference below F I F O </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue_lbl" xml:lang="en-US"> Inventory valuation, difference below FIFO </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectOfLIFOInventoryLiquidationOnIncome" xlink:label="us-gaap_EffectOfLIFOInventoryLiquidationOnIncome"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectOfLIFOInventoryLiquidationOnIncome" xlink:to="us-gaap_EffectOfLIFOInventoryLiquidationOnIncome_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectOfLIFOInventoryLiquidationOnIncome_lbl" xml:lang="en-US"> Effect of LIFO Inventory Liquidation on Income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectOfLIFOInventoryLiquidationOnIncome_lbl" xml:lang="en-US"> Liquidation of LIFO layer </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FIFOInventoryAmount" xlink:label="us-gaap_FIFOInventoryAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FIFOInventoryAmount" xlink:to="us-gaap_FIFOInventoryAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FIFOInventoryAmount_lbl" xml:lang="en-US"> FIFO Inventory Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FIFOInventoryAmount_lbl" xml:lang="en-US"> FIFO inventory amount </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryFinishedGoods" xlink:label="us-gaap_InventoryFinishedGoods"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoods" xlink:to="us-gaap_InventoryFinishedGoods_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryFinishedGoods_lbl" xml:lang="en-US"> Finished goods </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryLIFOReservePeriodCharge" xlink:label="us-gaap_InventoryLIFOReservePeriodCharge"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryLIFOReservePeriodCharge" xlink:to="us-gaap_InventoryLIFOReservePeriodCharge_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryLIFOReservePeriodCharge_lbl" xml:lang="en-US"> Cost of sales, valuation difference under F I F O </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryLIFOReservePeriodCharge_lbl" xml:lang="en-US"> Cost of Sales </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InventoryLIFOReserveEffectOnIncomeNet" xlink:label="us-gaap_InventoryLIFOReserveEffectOnIncomeNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryLIFOReserveEffectOnIncomeNet" xlink:to="us-gaap_InventoryLIFOReserveEffectOnIncomeNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryLIFOReserveEffectOnIncomeNet_lbl" xml:lang="en-US"> Net earnings, valuation difference under F I F O </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryLIFOReserveEffectOnIncomeNet_lbl" xml:lang="en-US"> Net Earnings </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_InventoryLifoReserveEffectOnEarningsPerShare" xlink:label="npk_InventoryLifoReserveEffectOnEarningsPerShare"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_InventoryLifoReserveEffectOnEarningsPerShare" xlink:to="npk_InventoryLifoReserveEffectOnEarningsPerShare_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_InventoryLifoReserveEffectOnEarningsPerShare_lbl" xml:lang="en-US"> Inventory, LIFO Reserve, Effect on Earnings Per Share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_InventoryLifoReserveEffectOnEarningsPerShare_lbl" xml:lang="en-US"> Inventory, LIFO Reserve, Effect on Earnings Per Share </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_InventoryLifoReserveEffectOnEarningsPerShare_lbl" xml:lang="en-US"> Earnings Per Share </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LossContingencyAccrualProductLiabilityGross" xlink:label="us-gaap_LossContingencyAccrualProductLiabilityGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingencyAccrualProductLiabilityGross" xlink:to="us-gaap_LossContingencyAccrualProductLiabilityGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LossContingencyAccrualProductLiabilityGross_lbl" xml:lang="en-US"> Loss Contingency Accrual, Product Liability, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LossContingencyAccrualProductLiabilityGross_lbl" xml:lang="en-US"> Accrued product liability </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Employee-related Liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US"> Accrued payroll liability </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingencies" xlink:label="us-gaap_AccrualForEnvironmentalLossContingencies"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingencies" xlink:to="us-gaap_AccrualForEnvironmentalLossContingencies_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingencies_lbl" xml:lang="en-US"> Accrual for Environmental Loss Contingencies </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingencies_lbl" xml:lang="en-US"> Environmental accrued liability </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xml:lang="en-US"> Other Accrued Liabilities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xml:lang="en-US"> Other accrued liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased" xlink:label="us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased" xlink:to="us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_lbl" xml:lang="en-US"> Stock Repurchase Program, Number of Shares Authorized to be Repurchased </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_lbl" xml:lang="en-US"> Shares approved for repurchase </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:to="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US"> Shares Paid for Tax Withholding for Share Based Compensation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US"> Shares Acquired From Participants For Share Based Compensation Tax Obligations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xml:lang="en-US"> Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardTypeAxis_lbl" xml:lang="en-US"> Award Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US"> Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US"> Equity Award [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockMember_lbl" xml:lang="en-US"> Restricted Stock [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RestrictedStockMember_lbl" xml:lang="en-US"> Restricted Stock [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xml:lang="en-US"> Shares authorized </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Shares granted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US"> Granted, Shares </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ShareBasedCompensationArrangementNumberOfPlanParticipants" xlink:label="npk_ShareBasedCompensationArrangementNumberOfPlanParticipants"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ShareBasedCompensationArrangementNumberOfPlanParticipants" xlink:to="npk_ShareBasedCompensationArrangementNumberOfPlanParticipants_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ShareBasedCompensationArrangementNumberOfPlanParticipants_lbl" xml:lang="en-US"> Number of plan participants </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ShareBasedCompensationArrangementNumberOfPlanParticipants_lbl" xml:lang="en-US"> Share-based Compensation Arrangement , Number of plan participants </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_ShareBasedCompensationArrangementNumberOfPlanParticipants_lbl" xml:lang="en-US"> Number of plan participants </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear" xlink:label="npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear" xlink:to="npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingYear_lbl" xml:lang="en-US"> Vesting year </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US"> Allocated Share-based Compensation Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US"> Pre-tax compensation expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xml:lang="en-US"> Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xml:lang="en-US"> Unrecognized compensation cost </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xml:lang="en-US"> Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xml:lang="en-US"> Unrecognized compensation cost, recognition period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US"> Vested, Shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US"> Shares vested </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US"> Non-vested at end of period, Shares </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US"> Non-vested at beginning of period, Shares </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US"> Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US"> Forfeited, Shares </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" 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 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Non-vested at end of period, Weighted Average Fair Value at Grant Date </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Non-vested at beginning of period, Weighted Average Fair Value at Grant Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" 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 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Granted, Weighted Average Fair Value at Grant Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" 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 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US"> Vested, Weighted Average Fair Value at Grant Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedContributionPlanTable" xlink:label="us-gaap_DefinedContributionPlanTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanTable" xlink:to="us-gaap_DefinedContributionPlanTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanTable_lbl" xml:lang="en-US"> Defined Contribution Plan [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedContributionPlanDisclosureLineItems" xlink:label="us-gaap_DefinedContributionPlanDisclosureLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanDisclosureLineItems" xlink:to="us-gaap_DefinedContributionPlanDisclosureLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanDisclosureLineItems_lbl" xml:lang="en-US"> Defined Contribution Plan Disclosure [Line Items] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_PercentageOfSpecifiedSalaryAmountMatchedByEmployer" xlink:label="npk_PercentageOfSpecifiedSalaryAmountMatchedByEmployer"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_PercentageOfSpecifiedSalaryAmountMatchedByEmployer" xlink:to="npk_PercentageOfSpecifiedSalaryAmountMatchedByEmployer_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_PercentageOfSpecifiedSalaryAmountMatchedByEmployer_lbl" xml:lang="en-US"> Percentage of specified salary amount matched by employer </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_PercentageOfSpecifiedSalaryAmountMatchedByEmployer_lbl" xml:lang="en-US"> Percentage of specified salary amount matched by employer </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" xml:lang="en-US"> Defined Contribution Plan, Employer Matching Contribution, Percent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" xml:lang="en-US"> Percentage of employee salary eligible for matching </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedContributionPlanCostRecognized" xlink:label="us-gaap_DefinedContributionPlanCostRecognized"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanCostRecognized" xlink:to="us-gaap_DefinedContributionPlanCostRecognized_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanCostRecognized_lbl" xml:lang="en-US"> Defined Benefit Plan, Contributions by Employer </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DefinedContributionPlanCostRecognized_lbl" xml:lang="en-US"> Employer contributions </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US"> Statutory rate </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate" xlink:to="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_lbl" xml:lang="en-US"> Increase in income tax provison from revaluation of net deferred tax assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US"> Unrecognized Tax Benefits </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US"> Balance at December 31 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US"> Balance at January 1 </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US"> Gross unrecognized tax benefits </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense" xlink:to="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_lbl" xml:lang="en-US"> Income Tax Examination, Penalties and Interest Accrued </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxExaminationPenaltiesAndInterestExpense_lbl" xml:lang="en-US"> Income tax related interest and penalties included in tax expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xml:lang="en-US"> Current Federal Tax Expense (Benefit) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xml:lang="en-US"> Current, Federal </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xml:lang="en-US"> Current State and Local Tax Expense (Benefit) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xml:lang="en-US"> Current, State </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Current Income Tax Expense (Benefit) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Current provision for income taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Deferred Federal Income Tax Expense (Benefit) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Deferred, Federal </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Deferred State and Local Income Tax Expense (Benefit) </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US"> Deferred, State </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities" xlink:label="npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities" xlink:to="npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities_lbl" xml:lang="en-US"> Deferred income tax expense benefit, including unrealized gain on available for sale securities. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities_lbl" xml:lang="en-US"> Deferred income tax expense benefit, including unrealized gain on available for sale securities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="npk_DeferredIncomeTaxExpenseBenefitIncludingUnrealizedGainOnAvailableForSaleSecurities_lbl" xml:lang="en-US"> Deferred provision for income taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, State and Local Income Taxes </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US"> State tax, net of federal benefit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Tax Exempt Income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome_lbl" xml:lang="en-US"> Tax exempt interest and dividends </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" xml:lang="en-US"> Effective Income Tax Rate Reconciliation, Other Adjustments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" xml:lang="en-US"> Other </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xml:lang="en-US"> Effective Income Tax Rate, Continuing Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xml:lang="en-US"> Effective Rate </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DeferredTaxAssetsInsurance" xlink:label="npk_DeferredTaxAssetsInsurance"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DeferredTaxAssetsInsurance" xlink:to="npk_DeferredTaxAssetsInsurance_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DeferredTaxAssetsInsurance_lbl" xml:lang="en-US"> Deferred tax assets, insurance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DeferredTaxAssetsInsurance_lbl" xml:lang="en-US"> Deferred tax assets, insurance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_DeferredTaxAssetsInsurance_lbl" xml:lang="en-US"> Insurance (primarily product liability) </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences_lbl" xml:lang="en-US"> Vacation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences_lbl" xml:lang="en-US"> Vacation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsInventory" xlink:label="us-gaap_DeferredTaxAssetsInventory"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsInventory" xlink:to="us-gaap_DeferredTaxAssetsInventory_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsInventory_lbl" xml:lang="en-US"> Deferred Tax Assets, Inventory </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsInventory_lbl" xml:lang="en-US"> Inventory </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation_lbl" xml:lang="en-US"> Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation_lbl" xml:lang="en-US"> Deferred compensation </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DeferredTaxAssetsEnvironmental" xlink:label="npk_DeferredTaxAssetsEnvironmental"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DeferredTaxAssetsEnvironmental" xlink:to="npk_DeferredTaxAssetsEnvironmental_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DeferredTaxAssetsEnvironmental_lbl" xml:lang="en-US"> Deferred tax assets, environmental </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DeferredTaxAssetsEnvironmental_lbl" xml:lang="en-US"> Deferred tax assets, environmental </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_DeferredTaxAssetsEnvironmental_lbl" xml:lang="en-US"> Environmental </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts_lbl" xml:lang="en-US"> Doubtful accounts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts_lbl" xml:lang="en-US"> Doubtful accounts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="us-gaap_DeferredTaxAssetsOther"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOther" xlink:to="us-gaap_DeferredTaxAssetsOther_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xml:lang="en-US"> Deferred Tax Assets, Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xml:lang="en-US"> Other </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNet" xlink:to="us-gaap_DeferredTaxAssetsNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xml:lang="en-US"> Deferred Tax Assets, Net of Valuation Allowance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xml:lang="en-US"> Total deferred tax assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:to="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl" xml:lang="en-US"> Deferred Tax Liabilities, Goodwill and Intangible Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl" xml:lang="en-US"> Goodwill and other intangibles </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DeferredTaxLiabilitiesDepreciation" xlink:label="npk_DeferredTaxLiabilitiesDepreciation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DeferredTaxLiabilitiesDepreciation" xlink:to="npk_DeferredTaxLiabilitiesDepreciation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DeferredTaxLiabilitiesDepreciation_lbl" xml:lang="en-US"> Deferred tax liabilities, depreciation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DeferredTaxLiabilitiesDepreciation_lbl" xml:lang="en-US"> Deferred tax liabilities, depreciation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_DeferredTaxLiabilitiesDepreciation_lbl" xml:lang="en-US"> Depreciation </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome" xlink:label="us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome" xlink:to="us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome_lbl" xml:lang="en-US"> Deferred Tax Liabilities, Tax Deferred Income </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome_lbl" xml:lang="en-US"> Deferred revenue </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="us-gaap_DeferredIncomeTaxLiabilities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilities" xlink:to="us-gaap_DeferredIncomeTaxLiabilities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xml:lang="en-US"> Deferred Tax Liabilities, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xml:lang="en-US"> Total deferred tax liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xml:lang="en-US"> Deferred Tax Assets, Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xml:lang="en-US"> Net deferred tax assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xml:lang="en-US"> Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xml:lang="en-US"> Increases for tax positions taken related to the current year </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US"> Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US"> Increases for tax positions taken related to prior years </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US"> Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US"> Decreases for tax positions taken related to prior years </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:to="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" xml:lang="en-US"> Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" xml:lang="en-US"> Lapse of statue of limitations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" xml:lang="en-US"> Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" xml:lang="en-US"> Settlements </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="us-gaap_ConcentrationRiskTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskTable" xlink:to="us-gaap_ConcentrationRiskTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskTable_lbl" xml:lang="en-US"> Concentration Risk [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="us-gaap_ConcentrationRiskLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskLineItems" xlink:to="us-gaap_ConcentrationRiskLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskLineItems_lbl" xml:lang="en-US"> Concentration Risk [Line Items] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_MajorCustomersContributingToNetSales" xlink:label="npk_MajorCustomersContributingToNetSales"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_MajorCustomersContributingToNetSales" xlink:to="npk_MajorCustomersContributingToNetSales_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_MajorCustomersContributingToNetSales_lbl" xml:lang="en-US"> Major customers contributing to net sales </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_MajorCustomersContributingToNetSales_lbl" xml:lang="en-US"> Major customers contributing to net sales </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskPercentage1" xlink:to="us-gaap_ConcentrationRiskPercentage1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xml:lang="en-US"> Net sales, major customer, percentage </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xml:lang="en-US"> Major customer, percentage </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_NumberOfEntityEmpolyeesUnionMembers" xlink:label="npk_NumberOfEntityEmpolyeesUnionMembers"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_NumberOfEntityEmpolyeesUnionMembers" xlink:to="npk_NumberOfEntityEmpolyeesUnionMembers_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_NumberOfEntityEmpolyeesUnionMembers_lbl" xml:lang="en-US"> Number of entity empolyees, union members </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_NumberOfEntityEmpolyeesUnionMembers_lbl" xml:lang="en-US"> Number of entity empolyees, union members </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_PercentageOfEntityEmployeesUnionMembers" xlink:label="npk_PercentageOfEntityEmployeesUnionMembers"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_PercentageOfEntityEmployeesUnionMembers" xlink:to="npk_PercentageOfEntityEmployeesUnionMembers_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_PercentageOfEntityEmployeesUnionMembers_lbl" xml:lang="en-US"> Percentage of entity employees, union members </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_PercentageOfEntityEmployeesUnionMembers_lbl" xml:lang="en-US"> Percentage of entity employees, union members </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear_lbl" xml:lang="en-US"> Other Commitment, Due in Next Twelve Months </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueWithinOneYear_lbl" xml:lang="en-US"> 2020 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInSecondYear" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInSecondYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInSecondYear" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInSecondYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInSecondYear_lbl" xml:lang="en-US"> Other Commitment, Due in Second Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInSecondYear_lbl" xml:lang="en-US"> 2021 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInThirdYear" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInThirdYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInThirdYear" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInThirdYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInThirdYear_lbl" xml:lang="en-US"> Other Commitment, Due in Third Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInThirdYear_lbl" xml:lang="en-US"> 2022 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFourthYear" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFourthYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFourthYear" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFourthYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFourthYear_lbl" xml:lang="en-US"> Other Commitment, Due in Fourth Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFourthYear_lbl" xml:lang="en-US"> 2023 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFifthYear" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFifthYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFifthYear" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFifthYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFifthYear_lbl" xml:lang="en-US"> Other Commitment, Due in Fifth Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueInFifthYear_lbl" xml:lang="en-US"> 2024 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueAfterFifthYear" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueAfterFifthYear"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueAfterFifthYear" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueAfterFifthYear_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueAfterFifthYear_lbl" xml:lang="en-US"> Other Commitment, Due after Fifth Year </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesUndiscountedDueAfterFifthYear_lbl" xml:lang="en-US"> Thereafter </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesGross" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesGross"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccrualForEnvironmentalLossContingenciesGross" xlink:to="us-gaap_AccrualForEnvironmentalLossContingenciesGross_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesGross_lbl" xml:lang="en-US"> Other Commitment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AccrualForEnvironmentalLossContingenciesGross_lbl" xml:lang="en-US"> Future payments for environmental matters </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfOperatingSegments" xlink:to="us-gaap_NumberOfOperatingSegments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xml:lang="en-US"> Number of Operating Segments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xml:lang="en-US"> Operating segments </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_GovernmentContractNumberOfContractors" xlink:label="npk_GovernmentContractNumberOfContractors"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_GovernmentContractNumberOfContractors" xlink:to="npk_GovernmentContractNumberOfContractors_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_GovernmentContractNumberOfContractors_lbl" xml:lang="en-US"> Government contract, number of contractors </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_GovernmentContractNumberOfContractors_lbl" xml:lang="en-US"> Government contract, number of contractors </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_SupplyCommitmentCommitmentTerm" xlink:label="npk_SupplyCommitmentCommitmentTerm"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_SupplyCommitmentCommitmentTerm" xlink:to="npk_SupplyCommitmentCommitmentTerm_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_SupplyCommitmentCommitmentTerm_lbl" xml:lang="en-US"> Supply commitment, commitment term </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_SupplyCommitmentCommitmentTerm_lbl" xml:lang="en-US"> Supply commitment, commitment term </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xml:lang="en-US"> Schedule of Segment Reporting Information, by Segment [Table] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_HousewaresSmallAppliancesMember" xlink:label="npk_HousewaresSmallAppliancesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_HousewaresSmallAppliancesMember" xlink:to="npk_HousewaresSmallAppliancesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_HousewaresSmallAppliancesMember_lbl" xml:lang="en-US"> Housewares/ small appliances. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_HousewaresSmallAppliancesMember_lbl" xml:lang="en-US"> Housewares Small Appliances [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_HousewaresSmallAppliancesMember_lbl" xml:lang="en-US"> Housewares/ Small Appliances [Member] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_SafetyMember" xlink:label="npk_SafetyMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_SafetyMember" xlink:to="npk_SafetyMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_SafetyMember_lbl" xml:lang="en-US"> Safety [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_SafetyMember_lbl" xml:lang="en-US"> Safety [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_SafetyMember_lbl" xml:lang="en-US"> Safety [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingInformationLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xml:lang="en-US"> Segment Reporting Information [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xml:lang="en-US"> Depreciation, Depletion and Amortization </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xml:lang="en-US"> Depreciation and amortization </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="us-gaap_PaymentsToAcquireProductiveAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireProductiveAssets" xlink:to="us-gaap_PaymentsToAcquireProductiveAssets_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireProductiveAssets_lbl" xml:lang="en-US"> Segment Reporting Information, Expenditures for Additions to Long-Lived Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PaymentsToAcquireProductiveAssets_lbl" xml:lang="en-US"> Capital expenditures </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeasesRentExpenseNet" xlink:label="us-gaap_OperatingLeasesRentExpenseNet"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesRentExpenseNet" xlink:to="us-gaap_OperatingLeasesRentExpenseNet_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesRentExpenseNet_lbl" xml:lang="en-US"> Operating Leases, Rent Expense, Net </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesRentExpenseNet_lbl" xml:lang="en-US"> Rent expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:label="us-gaap_OperatingLeasePayments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasePayments" xlink:to="us-gaap_OperatingLeasePayments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasePayments_lbl" xml:lang="en-US"> Operating Lease, Payments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasePayments_lbl" xml:lang="en-US"> Operating cash used for operating leases </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xml:lang="en-US"> Operating Lease, Weighted Average Remaining Lease Term </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xml:lang="en-US"> Weighted-average remaining lease term </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xml:lang="en-US"> Operating Lease, Weighted Average Discount Rate, Percent </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xml:lang="en-US"> Weighted average discount rate </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLeaseIncomeLeasePayments" xlink:label="us-gaap_OperatingLeaseLeaseIncomeLeasePayments"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLeaseIncomeLeasePayments" xlink:to="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl" xml:lang="en-US"> Operating Lease, Lease Income, Lease Payments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl" xml:lang="en-US"> Lease income from operating lease payments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseCost" xlink:label="us-gaap_OperatingLeaseCost"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseCost" xlink:to="us-gaap_OperatingLeaseCost_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseCost_lbl" xml:lang="en-US"> Operating lease cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseCost_lbl" xml:lang="en-US"> Operating lease cost </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ShortTermAndVariableLeaseCost" xlink:label="npk_ShortTermAndVariableLeaseCost"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ShortTermAndVariableLeaseCost" xlink:to="npk_ShortTermAndVariableLeaseCost_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ShortTermAndVariableLeaseCost_lbl" xml:lang="en-US"> Combined short-term and variable lease cost. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ShortTermAndVariableLeaseCost_lbl" xml:lang="en-US"> Short-term and variable lease cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_ShortTermAndVariableLeaseCost_lbl" xml:lang="en-US"> Short-term and variable lease cost </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LeaseCost" xlink:label="us-gaap_LeaseCost"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_LeaseCost_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseCost_lbl" xml:lang="en-US"> Total lease cost </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LeaseCost_lbl" xml:lang="en-US"> Total lease cost </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xml:lang="en-US"> Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xml:lang="en-US"> 2020 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xml:lang="en-US"> Year two </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xml:lang="en-US"> 2021 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xml:lang="en-US"> Year three </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xml:lang="en-US"> 2022 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xml:lang="en-US"> Year four </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xml:lang="en-US"> 2023 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xml:lang="en-US"> Year five </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xml:lang="en-US"> 2024 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xml:lang="en-US"> Lessee, Operating Lease, Liability, Payments, Due after Year Five </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xml:lang="en-US"> Thereafter </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xml:lang="en-US"> Total lease payments </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xml:lang="en-US"> Total lease payments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xml:lang="en-US"> Future interest expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xml:lang="en-US"> Less: future interest expense </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xml:lang="en-US"> Operating Lease, Liability </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xml:lang="en-US"> Lease liabilities </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_lbl" xml:lang="en-US"> Lessor, Operating Lease, Payments to be Received, Next Twelve Months </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_lbl" xml:lang="en-US"> 2020 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_lbl" xml:lang="en-US"> Two years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_lbl" xml:lang="en-US"> 2021 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_lbl" xml:lang="en-US"> Three years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_lbl" xml:lang="en-US"> 2022 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_lbl" xml:lang="en-US"> Four years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_lbl" xml:lang="en-US"> 2023 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_lbl" xml:lang="en-US"> Five years </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_lbl" xml:lang="en-US"> 2024 </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_lbl" xml:lang="en-US"> Lessor, Operating Lease, Payments to be Received, Thereafter </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_lbl" xml:lang="en-US"> Thereafter </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceived"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:to="us-gaap_LessorOperatingLeasePaymentsToBeReceived_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceived_lbl" xml:lang="en-US"> Lessor, Operating Lease, Payments to be Received </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LessorOperatingLeasePaymentsToBeReceived_lbl" xml:lang="en-US"> Total lease payments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityTable" xlink:label="us-gaap_LineOfCreditFacilityTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityTable" xlink:to="us-gaap_LineOfCreditFacilityTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityTable_lbl" xml:lang="en-US"> Line of Credit Facility [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityLineItems" xlink:label="us-gaap_LineOfCreditFacilityLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLineItems" xlink:to="us-gaap_LineOfCreditFacilityLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityLineItems_lbl" xml:lang="en-US"> Line of Credit Facility [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US"> Line of Credit Facility, Maximum Borrowing Capacity </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US"> Line of credit limit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherShortTermBorrowings" xlink:label="us-gaap_OtherShortTermBorrowings"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherShortTermBorrowings" xlink:to="us-gaap_OtherShortTermBorrowings_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherShortTermBorrowings_lbl" xml:lang="en-US"> Other Short-term Borrowings </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherShortTermBorrowings_lbl" xml:lang="en-US"> Line of credit outstanding </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:to="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xml:lang="en-US"> Debt Instrument, Basis Spread on Variable Rate </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xml:lang="en-US"> Percentage over LIBOR </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="us-gaap_LettersOfCreditOutstandingAmount"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LettersOfCreditOutstandingAmount" xlink:to="us-gaap_LettersOfCreditOutstandingAmount_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_lbl" xml:lang="en-US"> Letters of Credit Outstanding, Amount </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_lbl" xml:lang="en-US"> Letters of credit </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:to="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_lbl" xml:lang="en-US"> Disposal Groups, Including Discontinued Operations [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:to="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl" xml:lang="en-US"> Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:to="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Cash Provided by (Used in) Operating Activities, Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Cash provided by (used in) operating activities of discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:to="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Cash Provided by (Used in) Investing Activities, Discontinued Operations </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_lbl" xml:lang="en-US"> Cash provided by (used in) investing activities related to discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeaseTermOfContract" xlink:label="us-gaap_LessorOperatingLeaseTermOfContract"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeaseTermOfContract" xlink:to="us-gaap_LessorOperatingLeaseTermOfContract_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeaseTermOfContract_lbl" xml:lang="en-US"> Lessor Leasing Arrangements, Operating Leases, Term of Contract </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeaseTermOfContract_lbl" xml:lang="en-US"> Term of lease </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue" xlink:label="us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue" xlink:to="us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue_lbl" xml:lang="en-US"> Operating Leases, Income Statement, Minimum Lease Revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue_lbl" xml:lang="en-US"> Total annual lease payments </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeaseRenewalTerm" xlink:label="us-gaap_LessorOperatingLeaseRenewalTerm"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LessorOperatingLeaseRenewalTerm" xlink:to="us-gaap_LessorOperatingLeaseRenewalTerm_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LessorOperatingLeaseRenewalTerm_lbl" xml:lang="en-US"> Lessor, Operating Lease, Renewal Term </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LessorOperatingLeaseRenewalTerm_lbl" xml:lang="en-US"> Lease renewal period </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_LessorOperatingLeaseOptionToTerminateTerm" xlink:label="npk_LessorOperatingLeaseOptionToTerminateTerm"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_LessorOperatingLeaseOptionToTerminateTerm" xlink:to="npk_LessorOperatingLeaseOptionToTerminateTerm_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_LessorOperatingLeaseOptionToTerminateTerm_lbl" xml:lang="en-US"> Lessor leasing arrangement for operating leases - option to termminate term of contract. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_LessorOperatingLeaseOptionToTerminateTerm_lbl" xml:lang="en-US"> Lessor Operating Lease Option to Terminate Term </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="npk_LessorOperatingLeaseOptionToTerminateTerm_lbl" xml:lang="en-US"> Early termination term </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" xlink:to="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax_lbl" xml:lang="en-US"> Earnings from discontinued operations before provision for income taxes </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation" xlink:to="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl" xml:lang="en-US"> Discontinued Operation, Tax Effect of Discontinued Operation </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation_lbl" xml:lang="en-US"> Provision for income taxes from discontinued operations </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xml:lang="en-US"> Assets held for sale </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_lbl" xml:lang="en-US"> Disposal Group, Including Discontinued Operation, Consideration </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_lbl" xml:lang="en-US"> Consideration received for sale of business </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf" xlink:to="us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_lbl" xml:lang="en-US"> Impairment of Long-Lived Assets to be Disposed of </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_lbl" xml:lang="en-US"> Impairment of long-lived assets to be disposed of </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" xml:lang="en-US"> Schedule of Business Acquisitions, by Acquisition [Table] </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xml:lang="en-US"> Business acquisition, purchase price </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xml:lang="en-US"> Payments to Acquire Businesses, Gross </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xml:lang="en-US"> Business acquisition, purchase price, cash </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredOther1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredOther1"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredOther1" xlink:to="us-gaap_BusinessCombinationConsiderationTransferredOther1_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredOther1_lbl" xml:lang="en-US"> Business Combination, Consideration Transferred, Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredOther1_lbl" xml:lang="en-US"> Business acquisition, purchase price, forgiven note receivable </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_BusinessCombinationEarnOutEvaluationPeriod_lbl" xml:lang="en-US"> Business Combination, Earn Out Evaluation Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_BusinessCombinationEarnOutEvaluationPeriod_lbl" xml:lang="en-US"> Business Combination, Earn Out Evaluation Period </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xml:lang="en-US"> Business Combination, Contingent Consideration, Liability </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xml:lang="en-US"> Potential earn out payment </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US"> Acquired intangibles, amortization period </label>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US"> Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US"> Revenue of Acquiree Included in Consolidated Income Statement Since Acquisition Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual" xlink:label="us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US"> Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US"> Earnings of Acquiree Included in Consolidated Income Statement Since Acquisition Date </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xml:lang="en-US"> Cash </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_lbl" xml:lang="en-US"> Receivables </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl" xml:lang="en-US"> Inventory </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl" xml:lang="en-US"> Inventory </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl" xml:lang="en-US"> Other current assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xml:lang="en-US"> Property, plant and equipment </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_lbl" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_lbl" xml:lang="en-US"> Intangibles </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseLeaseAssets" xlink:label="npk_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseLeaseAssets"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseLeaseAssets" xlink:to="npk_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseLeaseAssets_lbl"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseLeaseAssets_lbl" xml:lang="en-US"> Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Right-of-Use Lease Assets </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseLeaseAssets_lbl" xml:lang="en-US"> Right-of-Use Lease Assets </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
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<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xml:lang="en-US"> Current Liabilities Assumed </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xml:lang="en-US"> Less: Current Liabilities Assumed </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation_lbl" xml:lang="en-US"> Lease Liability - Noncurrent </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_lbl" xml:lang="en-US"> Net Assets Acquired </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue_lbl" xml:lang="en-US"> Business Acquisition, Pro Forma Revenue </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue_lbl" xml:lang="en-US"> Net Sales </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax"/>
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<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" xml:lang="en-US"> Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" xml:lang="en-US"> Net Earnings </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" xlink:label="npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted" xlink:to="npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted_lbl" xml:lang="en-US"> Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted_lbl" xml:lang="en-US"> Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_BusinessAcquisitionProFormaEarningsPerShareBasicAndDiluted_lbl" xml:lang="en-US"> Net earnings per share (basic and diluted) </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US"> Legal Entity [Axis] </label>
<loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2018/dei-2018-01-31.xsd#dei_EntityDomain" xlink:label="dei_EntityDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityDomain" xlink:to="dei_EntityDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityDomain_lbl" xml:lang="en-US"> Entity [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_EntityDomain_lbl" xml:lang="en-US"> Entity [Domain] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ThirdPartyMember" xlink:label="npk_ThirdPartyMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ThirdPartyMember" xlink:to="npk_ThirdPartyMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ThirdPartyMember_lbl" xml:lang="en-US"> Unrelated third party member </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ThirdPartyMember_lbl" xml:lang="en-US"> Third Party [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_ThirdPartyMember_lbl" xml:lang="en-US"> Third Party [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="us-gaap_SubsequentEventTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTable_lbl" xml:lang="en-US"> Subsequent Event [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="us-gaap_SubsequentEventLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_SubsequentEventLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventLineItems_lbl" xml:lang="en-US"> Subsequent Event [Line Items] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_RegularDividendsPerShareDeclared" xlink:label="npk_RegularDividendsPerShareDeclared"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_RegularDividendsPerShareDeclared" xlink:to="npk_RegularDividendsPerShareDeclared_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_RegularDividendsPerShareDeclared_lbl" xml:lang="en-US"> Total amount of regular dividends declared per share during the period. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_RegularDividendsPerShareDeclared_lbl" xml:lang="en-US"> Regular Dividends Per Share, Declared </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_RegularDividendsPerShareDeclared_lbl" xml:lang="en-US"> Regular dividends per share, declared </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_ExtraDividendsPerShareDeclared" xlink:label="npk_ExtraDividendsPerShareDeclared"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_ExtraDividendsPerShareDeclared" xlink:to="npk_ExtraDividendsPerShareDeclared_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_ExtraDividendsPerShareDeclared_lbl" xml:lang="en-US"> Total amount of extra dividends declared per share during the period. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_ExtraDividendsPerShareDeclared_lbl" xml:lang="en-US"> Extra dividends per share, declared </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_ExtraDividendsPerShareDeclared_lbl" xml:lang="en-US"> Extra dividends per share, declared </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="srt_ValuationAndQualifyingAccountsDisclosureTable"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ValuationAndQualifyingAccountsDisclosureTable" xlink:to="srt_ValuationAndQualifyingAccountsDisclosureTable_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ValuationAndQualifyingAccountsDisclosureTable_lbl" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:to="srt_ValuationAndQualifyingAccountsDisclosureLineItems_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ValuationAndQualifyingAccountsDisclosureLineItems_lbl" xml:lang="en-US"> SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="srt_ValuationAndQualifyingAccountsDisclosureLineItems_lbl" xml:lang="en-US"> Valuation and Qualifying Accounts Disclosure [Line Items] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesBalance" xlink:to="us-gaap_ValuationAllowancesAndReservesBalance_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance_lbl" xml:lang="en-US"> Valuation Allowances and Reserves, Balance </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance_lbl" xml:lang="en-US"> Balance at End of Period </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance_lbl" xml:lang="en-US"> Balance at Beginning of Period </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:to="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl" xml:lang="en-US"> Valuation Allowances and Reserves, Charged to Cost and Expense </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl" xml:lang="en-US"> Additions, Charged to Costs and Expenses </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts" xlink:to="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_lbl" xml:lang="en-US"> Valuation Allowances and Reserves, Charged to Other Accounts </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_lbl" xml:lang="en-US"> Additions, Charged to Other Accounts </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="us-gaap_ValuationAllowancesAndReservesDeductions"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesDeductions" xlink:to="us-gaap_ValuationAllowancesAndReservesDeductions_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesDeductions_lbl" xml:lang="en-US"> Valuation Allowances and Reserves, Deductions </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesDeductions_lbl" xml:lang="en-US"> Deductions </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xml:lang="en-US"> Equity Components [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_EquityComponentDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityComponentDomain_lbl" xml:lang="en-US"> Equity Component [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquityComponentDomain_lbl" xml:lang="en-US"> Equity Component [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US"> Common Stock [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US"> Common Stock [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US"> Additional Paid In Capital [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US"> Paid-in Capital [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsMember_lbl" xml:lang="en-US"> Retained Earnings [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetainedEarningsMember_lbl" xml:lang="en-US"> Retained Earnings [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xml:lang="en-US"> Accumulated Other Comprehensive Income [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xml:lang="en-US"> Accumulated Comprehensive Income (Loss) [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="us-gaap_TreasuryStockMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockMember" xlink:to="us-gaap_TreasuryStockMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockMember_lbl" xml:lang="en-US"> Treasury Stock [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TreasuryStockMember_lbl" xml:lang="en-US"> Treasury Stock [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="us-gaap_BalanceSheetLocationAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationAxis" xlink:to="us-gaap_BalanceSheetLocationAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xml:lang="en-US"> Balance Sheet Location [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="us-gaap_BalanceSheetLocationDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationDomain" xlink:to="us-gaap_BalanceSheetLocationDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xml:lang="en-US"> Balance Sheet Location [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xml:lang="en-US"> Balance Sheet Location [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherCurrentAssetsMember" xlink:label="us-gaap_OtherCurrentAssetsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCurrentAssetsMember" xlink:to="us-gaap_OtherCurrentAssetsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherCurrentAssetsMember_lbl" xml:lang="en-US"> Other Current Assets [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherCurrentAssetsMember_lbl" xml:lang="en-US"> Other Current Assets [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US"> Property, Plant and Equipment, Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xml:lang="en-US"> Property Plant And Equipment Type [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xml:lang="en-US"> Property, Plant and Equipment, Type [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BuildingMember" xlink:label="us-gaap_BuildingMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BuildingMember" xlink:to="us-gaap_BuildingMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BuildingMember_lbl" xml:lang="en-US"> Building [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BuildingMember_lbl" xml:lang="en-US"> Buildings [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentMember" xlink:to="us-gaap_MachineryAndEquipmentMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xml:lang="en-US"> Machinery And Equipment [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xml:lang="en-US"> Machinery and Equipment [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LandImprovementsMember" xlink:label="us-gaap_LandImprovementsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LandImprovementsMember" xlink:to="us-gaap_LandImprovementsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LandImprovementsMember_lbl" xml:lang="en-US"> Land Improvements [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LandImprovementsMember_lbl" xml:lang="en-US"> Land Improvements [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:to="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_lbl" xml:lang="en-US"> Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetirementPlanNameAxis" xlink:label="us-gaap_RetirementPlanNameAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanNameAxis" xlink:to="us-gaap_RetirementPlanNameAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetirementPlanNameAxis_lbl" xml:lang="en-US"> Retirement Plan Name [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetirementPlanNameDomain" xlink:label="us-gaap_RetirementPlanNameDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanNameDomain" xlink:to="us-gaap_RetirementPlanNameDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetirementPlanNameDomain_lbl" xml:lang="en-US"> Retirement Plan Name [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetirementPlanNameDomain_lbl" xml:lang="en-US"> Retirement Plan Name [Domain] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_EmployerContributionCommonStockMember" xlink:label="npk_EmployerContributionCommonStockMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_EmployerContributionCommonStockMember" xlink:to="npk_EmployerContributionCommonStockMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_EmployerContributionCommonStockMember_lbl" xml:lang="en-US"> Employer Contribution Common Stock [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_EmployerContributionCommonStockMember_lbl" xml:lang="en-US"> Employer Contribution Common Stock [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_EmployerContributionCommonStockMember_lbl" xml:lang="en-US"> Employer Contribution Common Stock [Member] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_EmployerContributionCashMember" xlink:label="npk_EmployerContributionCashMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_EmployerContributionCashMember" xlink:to="npk_EmployerContributionCashMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_EmployerContributionCashMember_lbl" xml:lang="en-US"> Employer Contribution Cash [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_EmployerContributionCashMember_lbl" xml:lang="en-US"> Employer Contribution Cash [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_EmployerContributionCashMember_lbl" xml:lang="en-US"> Employer Contribution Cash [Member] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DefinedContributionPlanCertainEmployeesMember" xlink:label="npk_DefinedContributionPlanCertainEmployeesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DefinedContributionPlanCertainEmployeesMember" xlink:to="npk_DefinedContributionPlanCertainEmployeesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DefinedContributionPlanCertainEmployeesMember_lbl" xml:lang="en-US"> Defined Contribution Plan, Certain Employees [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DefinedContributionPlanCertainEmployeesMember_lbl" xml:lang="en-US"> Defined Contribution Plan Certain Employees [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_DefinedContributionPlanCertainEmployeesMember_lbl" xml:lang="en-US"> Certain Employees [Member] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_DefinedBenefitPlanUnionEmployeesMember" xlink:label="npk_DefinedBenefitPlanUnionEmployeesMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_DefinedBenefitPlanUnionEmployeesMember" xlink:to="npk_DefinedBenefitPlanUnionEmployeesMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_DefinedBenefitPlanUnionEmployeesMember_lbl" xml:lang="en-US"> Defined Benefit Plan, Union Employees [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_DefinedBenefitPlanUnionEmployeesMember_lbl" xml:lang="en-US"> Defined Benefit Plan Union Employees [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_DefinedBenefitPlanUnionEmployeesMember_lbl" xml:lang="en-US"> Defined Benefit Plan, Union Employees [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xml:lang="en-US"> Concentration Risk Benchmark [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xml:lang="en-US"> Concentration Risk Benchmark [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xml:lang="en-US"> Concentration Risk Benchmark [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SalesRevenueNetMember" xlink:to="us-gaap_SalesRevenueNetMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xml:lang="en-US"> Sales Revenue Net [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xml:lang="en-US"> Net Sales [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DiscontinuedOperationsHeldforsaleMember" xlink:label="us-gaap_DiscontinuedOperationsHeldforsaleMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationsHeldforsaleMember" xlink:to="us-gaap_DiscontinuedOperationsHeldforsaleMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DiscontinuedOperationsHeldforsaleMember_lbl" xml:lang="en-US"> Discontinued Operations Heldforsale [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DiscontinuedOperationsHeldforsaleMember_lbl" xml:lang="en-US"> Assets Held For Sale [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl" xml:lang="en-US"> Adjustments for New Accounting Pronouncements [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_TypeOfAdoptionMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xml:lang="en-US"> Type Of Adoption [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xml:lang="en-US"> Type of Adoption [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountingStandardsUpdate201602Member" xlink:label="us-gaap_AccountingStandardsUpdate201602Member"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingStandardsUpdate201602Member" xlink:to="us-gaap_AccountingStandardsUpdate201602Member_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingStandardsUpdate201602Member_lbl" xml:lang="en-US"> Accounting Standards Update201602 [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountingStandardsUpdate201602Member_lbl" xml:lang="en-US"> Accounting Standards Update 2016-02 [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CreditFacilityAxis_lbl" xml:lang="en-US"> Credit Facility [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_CreditFacilityDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CreditFacilityDomain_lbl" xml:lang="en-US"> Credit Facility [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CreditFacilityDomain_lbl" xml:lang="en-US"> Credit Facility [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DomesticLineOfCreditMember" xlink:label="us-gaap_DomesticLineOfCreditMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DomesticLineOfCreditMember" xlink:to="us-gaap_DomesticLineOfCreditMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DomesticLineOfCreditMember_lbl" xml:lang="en-US"> Domestic Line Of Credit [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DomesticLineOfCreditMember_lbl" xml:lang="en-US"> Domestic Line of Credit [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="us-gaap_DisposalGroupClassificationAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupClassificationAxis" xlink:to="us-gaap_DisposalGroupClassificationAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupClassificationAxis_lbl" xml:lang="en-US"> Disposal Group Classification [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="us-gaap_DisposalGroupClassificationDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupClassificationDomain" xlink:to="us-gaap_DisposalGroupClassificationDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupClassificationDomain_lbl" xml:lang="en-US"> Disposal Group Classification [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisposalGroupClassificationDomain_lbl" xml:lang="en-US"> Disposal Group Classification [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="us-gaap_StatementScenarioAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementScenarioAxis" xlink:to="us-gaap_StatementScenarioAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementScenarioAxis_lbl" xml:lang="en-US"> Statement, Scenario [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="us-gaap_ScenarioUnspecifiedDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScenarioUnspecifiedDomain" xlink:to="us-gaap_ScenarioUnspecifiedDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScenarioUnspecifiedDomain_lbl" xml:lang="en-US"> Scenario Unspecified [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScenarioUnspecifiedDomain_lbl" xml:lang="en-US"> Scenario, Unspecified [Domain] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_CurrentTwelveMonthEstimateMember" xlink:label="npk_CurrentTwelveMonthEstimateMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_CurrentTwelveMonthEstimateMember" xlink:to="npk_CurrentTwelveMonthEstimateMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_CurrentTwelveMonthEstimateMember_lbl" xml:lang="en-US"> Current twelve month estimate. </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_CurrentTwelveMonthEstimateMember_lbl" xml:lang="en-US"> Current Twelve Month Estimate [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_CurrentTwelveMonthEstimateMember_lbl" xml:lang="en-US"> Current twelve month estimate [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LeaseArrangementTypeAxis" xlink:label="us-gaap_LeaseArrangementTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseArrangementTypeAxis" xlink:to="us-gaap_LeaseArrangementTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseArrangementTypeAxis_lbl" xml:lang="en-US"> Lease Arrangement, Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LeaseArrangementTypeDomain" xlink:label="us-gaap_LeaseArrangementTypeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseArrangementTypeDomain" xlink:to="us-gaap_LeaseArrangementTypeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseArrangementTypeDomain_lbl" xml:lang="en-US"> Lease Arrangement Type [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LeaseArrangementTypeDomain_lbl" xml:lang="en-US"> Lease Arrangement, Type [Domain] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_OriginalLeaseAgreementMember" xlink:label="npk_OriginalLeaseAgreementMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_OriginalLeaseAgreementMember" xlink:to="npk_OriginalLeaseAgreementMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_OriginalLeaseAgreementMember_lbl" xml:lang="en-US"> Origianl lease agreement </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_OriginalLeaseAgreementMember_lbl" xml:lang="en-US"> Original Lease Agreement [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_OriginalLeaseAgreementMember_lbl" xml:lang="en-US"> Original lease agreement [Member] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_AmendedLeaseAgreementMember" xlink:label="npk_AmendedLeaseAgreementMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_AmendedLeaseAgreementMember" xlink:to="npk_AmendedLeaseAgreementMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_AmendedLeaseAgreementMember_lbl" xml:lang="en-US"> Amended lease agreement </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_AmendedLeaseAgreementMember_lbl" xml:lang="en-US"> Amended Lease Agreement [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_AmendedLeaseAgreementMember_lbl" xml:lang="en-US"> Amended lease agreement [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:label="us-gaap_StatementOperatingActivitiesSegmentAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:to="us-gaap_StatementOperatingActivitiesSegmentAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOperatingActivitiesSegmentAxis_lbl" xml:lang="en-US"> Operating Activities [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="us-gaap_SegmentOperatingActivitiesDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentOperatingActivitiesDomain" xlink:to="us-gaap_SegmentOperatingActivitiesDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentOperatingActivitiesDomain_lbl" xml:lang="en-US"> Segment Operating Activities [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentOperatingActivitiesDomain_lbl" xml:lang="en-US"> Operating Activities [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="us-gaap_SegmentDiscontinuedOperationsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDiscontinuedOperationsMember" xlink:to="us-gaap_SegmentDiscontinuedOperationsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentDiscontinuedOperationsMember_lbl" xml:lang="en-US"> Segment Discontinued Operations [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentDiscontinuedOperationsMember_lbl" xml:lang="en-US"> Discontinued Operations [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:label="us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember" xlink:to="us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_lbl" xml:lang="en-US"> Disposal Group Disposed Of By Sale Not Discontinued Operations [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_lbl" xml:lang="en-US"> Disposal Group, divestiture, not discontinued operations [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xml:lang="en-US"> Business Acquisition [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US"> Business Acquisition Acquiree [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US"> Business Acquisition, Acquiree [Domain] </label>
<loc xlink:type="locator" xlink:href="npk-20191231.xsd#npk_OneeventTechnologiesInc.Member" xlink:label="npk_OneeventTechnologiesInc.Member"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="npk_OneeventTechnologiesInc.Member" xlink:to="npk_OneeventTechnologiesInc.Member_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="npk_OneeventTechnologiesInc.Member_lbl" xml:lang="en-US"> OneEvent Technologies, Inc. [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="npk_OneeventTechnologiesInc.Member_lbl" xml:lang="en-US"> Oneevent Technologies Inc. [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="npk_OneeventTechnologiesInc.Member_lbl" xml:lang="en-US"> OneEvent Technologies, Inc. [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xml:lang="en-US"> Subsequent Event Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventTypeDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xml:lang="en-US"> Subsequent Event Type [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xml:lang="en-US"> Subsequent Event Type [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US"> Subsequent Event [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US"> Subsequent Event [Member] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:to="us-gaap_ValuationAllowancesAndReservesTypeAxis_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesTypeAxis_lbl" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="us-gaap_ValuationAllowancesAndReservesDomain"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesDomain" xlink:to="us-gaap_ValuationAllowancesAndReservesDomain_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesDomain_lbl" xml:lang="en-US"> Valuation Allowances And Reserves [Domain] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesDomain_lbl" xml:lang="en-US"> SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] </label>
<loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AllowanceForNotesReceivableMember" xlink:label="us-gaap_AllowanceForNotesReceivableMember"/>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForNotesReceivableMember" xlink:to="us-gaap_AllowanceForNotesReceivableMember_lbl"/>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForNotesReceivableMember_lbl" xml:lang="en-US"> Allowance For Notes Receivable [Member] </label>
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllowanceForNotesReceivableMember_lbl" xml:lang="en-US"> Allowance for Doubtful Accounts [Member] </label>
</labelLink>
</linkbase>

4 Subsequent Filings that Reference this Filing

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

 3/15/24  National Presto Industries Inc.   10-K       12/31/23   92:7.6M                                   RDG Filings/FA
 3/13/23  National Presto Industries Inc.   10-K       12/31/22   92:7.5M                                   RDG Filings/FA
 3/11/22  National Presto Industries Inc.   10-K       12/31/21   93:7.2M                                   RDG Filings/FA
 3/16/21  National Presto Industries Inc.   10-K       12/31/20   95:7.8M                                   RDG Filings/FA
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