SEC Info - Acme United Corp - ‘10-K’ for 12/31/18

SEC Info℠

Home

Help

Please Sign In

Acme United Corp – ‘10-K’ for 12/31/18 – ‘EX-101.DEF’

On: Friday, 3/15/19, at 5:02pm ET · For: 12/31/18 · Accession #: 1026608-19-11 · File #: 1-07698

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

 3/15/19  Acme United Corp                  10-K       12/31/18   89:4.3M                                   Placido Robert/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    403K 
 2: EX-21       Subsidiaries List                                   HTML     22K 
 3: EX-23.1     Consent of Experts or Counsel                       HTML     25K 
 4: EX-31.1     Certification -- §302 - SOA'02                      HTML     24K 
 5: EX-31.2     Certification -- §302 - SOA'02                      HTML     24K 
 6: EX-32.1     Certification -- §906 - SOA'02                      HTML     28K 
 7: EX-32.2     Certification -- §906 - SOA'02                      HTML     28K 
14: R1          Document and Entity Information                     HTML     57K 
15: R2          Consolidated Statements of Operations               HTML     73K 
16: R3          Consolidated Statements of Comprehensive Income     HTML     46K 
17: R4          Consolidated Balance Sheets                         HTML    122K 
18: R5          Consolidated Balance Sheets (Parenthetical)         HTML     33K 
19: R6          Consolidated Statements of Changes in               HTML     67K 
                Stockholders' Equity                                             
20: R7          Consolidated Statements of Cash Flows               HTML    108K 
21: R8          Operations                                          HTML     27K 
22: R9          Accounting Policies                                 HTML     44K 
23: R10         Inventories                                         HTML     29K 
24: R11         Intangible Assets and Goodwill                      HTML     36K 
25: R12         Other Accrued Liabilities                           HTML     29K 
26: R13         Pension and Profit Sharing                          HTML     68K 
27: R14         Income Taxes                                        HTML     56K 
28: R15         Long-Term Debt and Shareholders' Equity             HTML     30K 
29: R16         Commitments and Contingencies                       HTML     27K 
30: R17         Revenue from Contracts with Customers               HTML     44K 
31: R18         Segment Information                                 HTML     46K 
32: R19         Stock Option Plans                                  HTML     59K 
33: R20         Earnings Per Share                                  HTML     30K 
34: R21         Accumulated Other Comprehensive Loss                HTML     34K 
35: R22         Financial Instruments                               HTML     27K 
36: R23         Quarterly Data (Unaudited)                          HTML     45K 
37: R24         Business Combinations                               HTML     32K 
38: R25         Accounting Policies (Policies)                      HTML    103K 
39: R26         Inventories (Tables)                                HTML     30K 
40: R27         Intangible Assets and Goodwill (Tables)             HTML     35K 
41: R28         Other Accrued Liabilities (Tables)                  HTML     28K 
42: R29         Pension and Profit Sharing (Tables)                 HTML     73K 
43: R30         Income Taxes (Tables)                               HTML     54K 
44: R31         Revenue from Contracts with Customers (Tables)      HTML     32K 
45: R32         Segment Information (Tables)                        HTML     49K 
46: R33         Stock Option Plans (Tables)                         HTML     51K 
47: R34         Earnings Per Share (Tables)                         HTML     30K 
48: R35         Accumulated Other Comprehensive (Loss) Income       HTML     33K 
                (Tables)                                                         
49: R36         Quarterly Data (Tables)                             HTML     44K 
50: R37         Business Combinations - Business Combinations       HTML     30K 
                (Tables)                                                         
51: R38         Accounting Policies - Accounting Policies (Detail   HTML     55K 
                Narrative)                                                       
52: R39         Inventories (Details Narrative)                     HTML     26K 
53: R40         Inventories - Inventories (Details)                 HTML     36K 
54: R41         Intangible Assets and Goodwill (Details Narrative)  HTML     41K 
55: R42         Intangible Assets and Goodwill - Intangible Assets  HTML     60K 
                (Details)                                                        
56: R43         Other Accrued Liabilities (Details)                 HTML     41K 
57: R44         Pension and Profit Sharing - Plan Asset Allocation  HTML     29K 
                (Details)                                                        
58: R45         Pension and Profit Sharing - Pension Plan Assets    HTML     42K 
                by Fair Value Hiearchy (Details)                                 
59: R46         Pension and Profit Sharing - Benefit Obligation     HTML     43K 
                (Details)                                                        
60: R47         Pension And Profit Sharing - Changes In Plan        HTML     40K 
                Assets (Details)                                                 
61: R48         Pension and Profit Sharing - Periodic Benefit Cost  HTML     49K 
                (Details)                                                        
62: R49         Pension and Profit Sharing - Amounts Recognized in  HTML     48K 
                Other Comprehensive Income (Details)                             
63: R50         Pension and Profit Sharing - Estimated Future       HTML     37K 
                Benefit Payments (Details)                                       
64: R51         Pension and Profit Sharing (Details Narrative)      HTML     42K 
65: R52         Income Taxes (Details Narrative)                    HTML     45K 
66: R53         Income Taxes - Income Tax Expense (Benefit)         HTML     50K 
                (Details)                                                        
67: R54         Income Taxes - US and Foreign Income Before Income  HTML     31K 
                Taxes (Details)                                                  
68: R55         Income Taxes - US Statutory Rate Reconciliation     HTML     46K 
                (Details)                                                        
69: R56         Income Taxes - Deferred Tax Assets and Liabilities  HTML     44K 
                (Details)                                                        
70: R57         Long-Term Debt (Details Narrative)                  HTML     84K 
71: R58         Commitments and Contingencies (Details Narrative)   HTML     45K 
72: R59         Revenue from Contracts with Customers (Details)     HTML     34K 
73: R60         Segment Information (Details Narrative)             HTML     25K 
74: R61         Segment Information - Financial Data by Segment     HTML     52K 
                (Details)                                                        
75: R62         Reconciliation of Segment Operating Income          HTML     34K 
                (Details)                                                        
76: R63         Segment Revenues (Details)                          HTML     38K 
77: R64         Stock Option Plans (Details Narrative)              HTML     65K 
78: R65         Stock Option Plans - Stock Option Activity          HTML     54K 
                (Details)                                                        
79: R66         Stock Option Plans - Summary of Options             HTML     60K 
                Outstanding (Details)                                            
80: R67         Stock Option Plans - Assumptions Used to Value      HTML     38K 
                Option Grants (Details)                                          
81: R68         Earnings Per Share (Details Narrative)              HTML     26K 
82: R69         Earnings Per Share - Earnings Per Share (Details)   HTML     51K 
83: R70         Comprehensive Income - Accumulated Other            HTML     38K 
                Comprehensive (Loss) Income (Details)                            
84: R71         Quarterly Data - Quarterly Data (Details)           HTML     53K 
85: R72         Business Combination (Details Narrative)            HTML     42K 
86: R73         Business Combination Purchase Price Allocation      HTML     42K 
                (Details)                                                        
88: XML         IDEA XML File -- Filing Summary                      XML    155K 
87: EXCEL       IDEA Workbook of Financial Reports                  XLSX     82K 
 8: EX-101.INS  XBRL Instance -- acu-20181231                        XML   1.14M 
10: EX-101.CAL  XBRL Calculations -- acu-20181231_cal                XML    248K 
11: EX-101.DEF  XBRL Definitions -- acu-20181231_def                 XML    365K 
12: EX-101.LAB  XBRL Labels -- acu-20181231_lab                      XML    989K 
13: EX-101.PRE  XBRL Presentations -- acu-20181231_pre               XML    763K 
 9: EX-101.SCH  XBRL Schema -- acu-20181231                          XSD    152K 
89: ZIP         XBRL Zipped Folder -- 0001026608-19-000011-xbrl      Zip    126K

‘EX-101.DEF’ — XBRL Definitions — acu-20181231_def

This Exhibit is an XBRL XML File.

<?xml version="1.0" standalone="no" encoding="windows-1252"?>

<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">

<link:roleRef roleURI="http://acu.com/role/DocumentAndEntityInformation" xlink:href="acu-20181231.xsd#DocumentAndEntityInformation" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StatementsOfOperations" xlink:href="acu-20181231.xsd#StatementsOfOperations" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StatementsOfComprehensiveIncome" xlink:href="acu-20181231.xsd#StatementsOfComprehensiveIncome" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/BalanceSheets" xlink:href="acu-20181231.xsd#BalanceSheets" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/BalanceSheetsParenthetical" xlink:href="acu-20181231.xsd#BalanceSheetsParenthetical" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StatementsOfChangesInStockholdersEquity" xlink:href="acu-20181231.xsd#StatementsOfChangesInStockholdersEquity" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StatementsOfCashFlows" xlink:href="acu-20181231.xsd#StatementsOfCashFlows" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/Operations" xlink:href="acu-20181231.xsd#Operations" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/AccountingPolicies" xlink:href="acu-20181231.xsd#AccountingPolicies" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/Inventories" xlink:href="acu-20181231.xsd#Inventories" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IntangibleAssetsAndGoodwill" xlink:href="acu-20181231.xsd#IntangibleAssetsAndGoodwill" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/OtherAccruedLiabilities" xlink:href="acu-20181231.xsd#OtherAccruedLiabilities" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing" xlink:href="acu-20181231.xsd#PensionAndProfitSharing" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxes" xlink:href="acu-20181231.xsd#IncomeTaxes" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/Long-termDebtAndShareholdersEquity" xlink:href="acu-20181231.xsd#Long-termDebtAndShareholdersEquity" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/CommitmentsAndContingencies" xlink:href="acu-20181231.xsd#CommitmentsAndContingencies" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/RevenueFromContractsWithCustomers" xlink:href="acu-20181231.xsd#RevenueFromContractsWithCustomers" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/SegmentInformation" xlink:href="acu-20181231.xsd#SegmentInformation" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StockOptionPlans" xlink:href="acu-20181231.xsd#StockOptionPlans" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/EarningsPerShare" xlink:href="acu-20181231.xsd#EarningsPerShare" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/AccumulatedOtherComprehensiveLoss" xlink:href="acu-20181231.xsd#AccumulatedOtherComprehensiveLoss" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/FinancialInstruments" xlink:href="acu-20181231.xsd#FinancialInstruments" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/QuarterlyData" xlink:href="acu-20181231.xsd#QuarterlyData" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/BusinessCombinations" xlink:href="acu-20181231.xsd#BusinessCombinations" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/AccountingPoliciesPolicies" xlink:href="acu-20181231.xsd#AccountingPoliciesPolicies" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/InventoriesTables" xlink:href="acu-20181231.xsd#InventoriesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IntangibleAssetsAndGoodwillTables" xlink:href="acu-20181231.xsd#IntangibleAssetsAndGoodwillTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/OtherAccruedLiabilitiesTables" xlink:href="acu-20181231.xsd#OtherAccruedLiabilitiesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharingTables" xlink:href="acu-20181231.xsd#PensionAndProfitSharingTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxesTables" xlink:href="acu-20181231.xsd#IncomeTaxesTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/RevenueFromContractsWithCustomersTables" xlink:href="acu-20181231.xsd#RevenueFromContractsWithCustomersTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/SegmentInformationTables" xlink:href="acu-20181231.xsd#SegmentInformationTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StockOptionPlansTables" xlink:href="acu-20181231.xsd#StockOptionPlansTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/EarningsPerShareTables" xlink:href="acu-20181231.xsd#EarningsPerShareTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/AccumulatedOtherComprehensiveLossIncomeTables" xlink:href="acu-20181231.xsd#AccumulatedOtherComprehensiveLossIncomeTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/QuarterlyDataTables" xlink:href="acu-20181231.xsd#QuarterlyDataTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/BusinessCombinations-BusinessCombinationsTables" xlink:href="acu-20181231.xsd#BusinessCombinations-BusinessCombinationsTables" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/AccountingPolicies-AccountingPoliciesDetailNarrative" xlink:href="acu-20181231.xsd#AccountingPolicies-AccountingPoliciesDetailNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/InventoriesDetailsNarrative" xlink:href="acu-20181231.xsd#InventoriesDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/Inventories-InventoriesDetails" xlink:href="acu-20181231.xsd#Inventories-InventoriesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IntangibleAssetsAndGoodwillDetailsNarrative" xlink:href="acu-20181231.xsd#IntangibleAssetsAndGoodwillDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IntangibleAssetsAndGoodwill-IntangibleAssetsDetails" xlink:href="acu-20181231.xsd#IntangibleAssetsAndGoodwill-IntangibleAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/OtherAccruedLiabilitiesDetails" xlink:href="acu-20181231.xsd#OtherAccruedLiabilitiesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-PlanAssetAllocationDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-PlanAssetAllocationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-PensionPlanAssetsByFairValueHiearchyDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-PensionPlanAssetsByFairValueHiearchyDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-BenefitObligationDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-BenefitObligationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-ChangesInPlanAssetsDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-ChangesInPlanAssetsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-PeriodicBenefitCostDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-PeriodicBenefitCostDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-AmountsRecognizedInOtherComprehensiveIncomeDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-AmountsRecognizedInOtherComprehensiveIncomeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharing-EstimatedFutureBenefitPaymentsDetails" xlink:href="acu-20181231.xsd#PensionAndProfitSharing-EstimatedFutureBenefitPaymentsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/PensionAndProfitSharingDetailsNarrative" xlink:href="acu-20181231.xsd#PensionAndProfitSharingDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxesDetailsNarrative" xlink:href="acu-20181231.xsd#IncomeTaxesDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxes-IncomeTaxExpenseBenefitDetails" xlink:href="acu-20181231.xsd#IncomeTaxes-IncomeTaxExpenseBenefitDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxes-UsAndForeignIncomeBeforeIncomeTaxesDetails" xlink:href="acu-20181231.xsd#IncomeTaxes-UsAndForeignIncomeBeforeIncomeTaxesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxes-UsStatutoryRateReconciliationDetails" xlink:href="acu-20181231.xsd#IncomeTaxes-UsStatutoryRateReconciliationDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/IncomeTaxes-DeferredTaxAssetsAndLiabilitiesDetails" xlink:href="acu-20181231.xsd#IncomeTaxes-DeferredTaxAssetsAndLiabilitiesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/Long-termDebtDetailsNarrative" xlink:href="acu-20181231.xsd#Long-termDebtDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/CommitmentsAndContingenciesDetailsNarrative" xlink:href="acu-20181231.xsd#CommitmentsAndContingenciesDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/RevenueFromContractsWithCustomersDetails" xlink:href="acu-20181231.xsd#RevenueFromContractsWithCustomersDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/SegmentInformationDetailsNarrative" xlink:href="acu-20181231.xsd#SegmentInformationDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/SegmentInformation-FinancialDataBySegmentDetails" xlink:href="acu-20181231.xsd#SegmentInformation-FinancialDataBySegmentDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/ReconciliationOfSegmentOperatingIncomeDetails" xlink:href="acu-20181231.xsd#ReconciliationOfSegmentOperatingIncomeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/SegmentRevenuesDetails" xlink:href="acu-20181231.xsd#SegmentRevenuesDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StockOptionPlansDetailsNarrative" xlink:href="acu-20181231.xsd#StockOptionPlansDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StockOptionPlans-StockOptionActivityDetails" xlink:href="acu-20181231.xsd#StockOptionPlans-StockOptionActivityDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StockOptionPlans-SummaryOfOptionsOutstandingDetails" xlink:href="acu-20181231.xsd#StockOptionPlans-SummaryOfOptionsOutstandingDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/StockOptionPlans-AssumptionsUsedToValueOptionGrantsDetails" xlink:href="acu-20181231.xsd#StockOptionPlans-AssumptionsUsedToValueOptionGrantsDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/EarningsPerShareDetailsNarrative" xlink:href="acu-20181231.xsd#EarningsPerShareDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/EarningsPerShare-EarningsPerShareDetails" xlink:href="acu-20181231.xsd#EarningsPerShare-EarningsPerShareDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/ComprehensiveIncome-AccumulatedOtherComprehensiveLossIncomeDetails" xlink:href="acu-20181231.xsd#ComprehensiveIncome-AccumulatedOtherComprehensiveLossIncomeDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/QuarterlyData-QuarterlyDataDetails" xlink:href="acu-20181231.xsd#QuarterlyData-QuarterlyDataDetails" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/BusinessCombinationDetailsNarrative" xlink:href="acu-20181231.xsd#BusinessCombinationDetailsNarrative" xlink:type="simple"/>

<link:roleRef roleURI="http://acu.com/role/BusinessCombinationPurchasePriceAllocationDetails" xlink:href="acu-20181231.xsd#BusinessCombinationPurchasePriceAllocationDetails" xlink:type="simple"/>

<link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension"/>

<link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain"/>

<link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member"/>

<link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all"/>

<link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" arcroleURI="http://xbrl.org/int/dim/arcrole/notAll"/>

<link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/DocumentAndEntityInformation" xlink:title="00000001 - Document - Document and Entity Information"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/StatementsOfOperations" xlink:title="00000002 - Statement - Consolidated Statements of Operations"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/StatementsOfComprehensiveIncome" xlink:title="00000003 - Statement - Consolidated Statements of Comprehensive Income"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/BalanceSheets" xlink:title="00000004 - Statement - Consolidated Balance Sheets"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/BalanceSheetsParenthetical" xlink:title="00000005 - Statement - Consolidated Balance Sheets (Parenthetical)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/StatementsOfChangesInStockholdersEquity" xlink:title="00000006 - Statement - Consolidated Statements of Changes in Stockholders' Equity">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStatementTable" xlink:type="arc" order="10" xbrldt:closed="true"/>

<link: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="loc_us-gaapStatementEquityComponentsAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="1"/>

<link: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="loc_us-gaapEquityComponentDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20"/>

<link: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="loc_us-gaapEquityComponentDomain_10"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30"/>

<link: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="loc_us-gaapCommonStockMember_0"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapCommonStockMember_0" xlink:type="arc" order="1"/>

<link: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="loc_us-gaapTreasuryStockMember_10"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapTreasuryStockMember_10" xlink:type="arc" order="11"/>

<link: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="loc_us-gaapAdditionalPaidInCapitalMember_20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapAdditionalPaidInCapitalMember_20" xlink:type="arc" order="21"/>

<link: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="loc_us-gaapAccumulatedOtherComprehensiveIncomeMember_30"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapAccumulatedOtherComprehensiveIncomeMember_30" xlink:type="arc" order="31"/>

<link: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="loc_us-gaapRetainedEarningsMember_40"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapRetainedEarningsMember_40" xlink:type="arc" order="41"/>

<link: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="loc_us-gaapStockholdersEquity_70"/>

<link: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="loc_us-gaapCommonStockSharesOutstanding_70"/>

<link: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="loc_us-gaapNetIncomeLoss_70"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaapOtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_70"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapOtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_70" xlink:type="arc" order="5"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaapAdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_70"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapAdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_70" xlink:type="arc" order="6"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet" xlink:label="loc_us-gaapAdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet_70"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapAdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet_70" xlink:type="arc" order="7"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaapDividendsCommonStockCash_70"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaapStockIssuedDuringPeriodValueStockOptionsExercised_70"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodValueStockOptionsExercised_70" xlink:type="arc" order="9"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaapStockIssuedDuringPeriodSharesStockOptionsExercised_70"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodSharesStockOptionsExercised_70" xlink:type="arc" order="10"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_PaymentsRelatedToCashSettlementOfShareBasedCompensation" xlink:label="loc_ACUPaymentsRelatedToCashSettlementOfShareBasedCompensation_70"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUPaymentsRelatedToCashSettlementOfShareBasedCompensation_70" xlink:type="arc" order="11"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaapStockRepurchasedDuringPeriodValue_70"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaapStockRepurchasedDuringPeriodShares_70"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/StatementsOfCashFlows" xlink:title="00000007 - Statement - Consolidated Statements of Cash Flows"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/Operations" xlink:title="00000008 - Disclosure - Operations"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/AccountingPolicies" xlink:title="00000009 - Disclosure - Accounting Policies"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/Inventories" xlink:title="00000010 - Disclosure - Inventories"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IntangibleAssetsAndGoodwill" xlink:title="00000011 - Disclosure - Intangible Assets and Goodwill"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/OtherAccruedLiabilities" xlink:title="00000012 - Disclosure - Other Accrued Liabilities"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing" xlink:title="00000013 - Disclosure - Pension and Profit Sharing"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxes" xlink:title="00000014 - Disclosure - Income Taxes"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/Long-termDebtAndShareholdersEquity" xlink:title="00000015 - Disclosure - Long-Term Debt and Shareholders' Equity"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/CommitmentsAndContingencies" xlink:title="00000016 - Disclosure - Commitments and Contingencies"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/RevenueFromContractsWithCustomers" xlink:title="00000017 - Disclosure - Revenue from Contracts with Customers"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/SegmentInformation" xlink:title="00000018 - Disclosure - Segment Information"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/StockOptionPlans" xlink:title="00000019 - Disclosure - Stock Option Plans"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/EarningsPerShare" xlink:title="00000020 - Disclosure - Earnings Per Share"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/AccumulatedOtherComprehensiveLoss" xlink:title="00000021 - Disclosure - Accumulated Other Comprehensive Loss"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/FinancialInstruments" xlink:title="00000022 - Disclosure - Financial Instruments"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/QuarterlyData" xlink:title="00000023 - Disclosure - Quarterly Data (unaudited)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/BusinessCombinations" xlink:title="00000024 - Disclosure - Business Combinations"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/AccountingPoliciesPolicies" xlink:title="00000025 - Disclosure - Accounting Policies (Policies)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/InventoriesTables" xlink:title="00000026 - Disclosure - Inventories (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IntangibleAssetsAndGoodwillTables" xlink:title="00000027 - Disclosure - Intangible Assets and Goodwill (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/OtherAccruedLiabilitiesTables" xlink:title="00000028 - Disclosure - Other Accrued Liabilities (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharingTables" xlink:title="00000029 - Disclosure - Pension and Profit Sharing (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxesTables" xlink:title="00000030 - Disclosure - Income Taxes (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/RevenueFromContractsWithCustomersTables" xlink:title="00000031 - Disclosure - Revenue from Contracts with Customers (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/SegmentInformationTables" xlink:title="00000032 - Disclosure - Segment Information (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/StockOptionPlansTables" xlink:title="00000033 - Disclosure - Stock Option Plans (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/EarningsPerShareTables" xlink:title="00000034 - Disclosure - Earnings Per Share (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/AccumulatedOtherComprehensiveLossIncomeTables" xlink:title="00000035 - Disclosure - Accumulated Other Comprehensive (Loss) Income (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/QuarterlyDataTables" xlink:title="00000036 - Disclosure - Quarterly Data (Tables)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/BusinessCombinations-BusinessCombinationsTables" xlink:title="00000037 - Disclosure - Business Combinations - Business Combinations (Tables)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link: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="loc_us-gaapBusinessAcquisitionAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapBusinessAcquisitionAxis" xlink:type="arc" order="1"/>

<link: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="loc_us-gaapBusinessAcquisitionAcquireeDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapBusinessAcquisitionAxis" xlink:to="loc_us-gaapBusinessAcquisitionAcquireeDomain" xlink:type="arc" order="20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapBusinessAcquisitionAxis" xlink:to="loc_us-gaapBusinessAcquisitionAcquireeDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_SeriesOfIndividuallyImmaterialBusinessAcquisitionsDMember" xlink:label="loc_ACUSeriesOfIndividuallyImmaterialBusinessAcquisitionsDMember_0"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapBusinessAcquisitionAcquireeDomain" xlink:to="loc_ACUSeriesOfIndividuallyImmaterialBusinessAcquisitionsDMember_0" xlink:type="arc" order="1"/>

<link: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="loc_us-gaapScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_20" xlink:type="arc" order="2"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/AccountingPolicies-AccountingPoliciesDetailNarrative" xlink:title="00000038 - Disclosure - Accounting Policies - Accounting Policies (Detail Narrative)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeAxis" xlink:label="loc_srtRangeAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtRangeAxis" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember" xlink:type="arc" order="20"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember_10"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MinimumMember" xlink:label="loc_srtMinimumMember_40"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMinimumMember_40" xlink:type="arc" order="41"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_MaximumMember" xlink:label="loc_srtMaximumMember_50"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMaximumMember_50" xlink:type="arc" order="51"/>

<link: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="loc_us-gaapConcentrationRiskByBenchmarkAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapConcentrationRiskByBenchmarkAxis" xlink:type="arc" order="2"/>

<link: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="loc_us-gaapConcentrationRiskBenchmarkDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapConcentrationRiskByBenchmarkAxis" xlink:to="loc_us-gaapConcentrationRiskBenchmarkDomain" xlink:type="arc" order="20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapConcentrationRiskByBenchmarkAxis" xlink:to="loc_us-gaapConcentrationRiskBenchmarkDomain_10" xlink:type="arc" order="30"/>

<link: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="loc_us-gaapSalesRevenueNetMember_60"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapConcentrationRiskBenchmarkDomain" xlink:to="loc_us-gaapSalesRevenueNetMember_60" xlink:type="arc" order="61"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaapConcentrationRiskByTypeAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapConcentrationRiskByTypeAxis" xlink:type="arc" order="3"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaapConcentrationRiskTypeDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapConcentrationRiskByTypeAxis" xlink:to="loc_us-gaapConcentrationRiskTypeDomain" xlink:type="arc" order="20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapConcentrationRiskByTypeAxis" xlink:to="loc_us-gaapConcentrationRiskTypeDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="loc_us-gaapCustomerConcentrationRiskMember_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapConcentrationRiskTypeDomain" xlink:to="loc_us-gaapCustomerConcentrationRiskMember_80" xlink:type="arc" order="81"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_CustomerConcentrationRiskAMember" xlink:label="loc_ACUCustomerConcentrationRiskAMember_100"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapConcentrationRiskTypeDomain" xlink:to="loc_ACUCustomerConcentrationRiskAMember_100" xlink:type="arc" order="101"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srtProductOrServiceAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtProductOrServiceAxis" xlink:type="arc" order="4"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain" xlink:type="arc" order="20"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain_10"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="loc_us-gaapForeignCurrencyTransactionGainLossBeforeTax_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapForeignCurrencyTransactionGainLossBeforeTax_130" xlink:type="arc" order="0"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CertificatesOfDepositAtCarryingValue" xlink:label="loc_us-gaapCertificatesOfDepositAtCarryingValue_130"/>

<link: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="loc_us-gaapAllowanceForDoubtfulAccountsReceivable_130"/>

<link: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="loc_us-gaapPropertyPlantAndEquipmentUsefulLife_130"/>

<link: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="loc_us-gaapFiniteLivedIntangibleAssetUsefulLife_130"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaapResearchAndDevelopmentExpense_130"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_CostOfGoodsAndServicesSoldShippingAndHandling" xlink:label="loc_ACUCostOfGoodsAndServicesSoldShippingAndHandling_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUCostOfGoodsAndServicesSoldShippingAndHandling_130" xlink:type="arc" order="6"/>

<link: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="loc_us-gaapAdvertisingExpense_130"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_ConcentrationRiskNumberOfMajorCustomers" xlink:label="loc_ACUConcentrationRiskNumberOfMajorCustomers_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUConcentrationRiskNumberOfMajorCustomers_130" xlink:type="arc" order="8"/>

<link: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="loc_us-gaapConcentrationRiskPercentage1_130"/>

<link: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="loc_us-gaapOperatingLeaseRightOfUseAsset_130"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/InventoriesDetailsNarrative" xlink:title="00000039 - Disclosure - Inventories (Details Narrative)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/Inventories-InventoriesDetails" xlink:title="00000040 - Disclosure - Inventories - Inventories (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IntangibleAssetsAndGoodwillDetailsNarrative" xlink:title="00000041 - Disclosure - Intangible Assets and Goodwill (Details Narrative)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IntangibleAssetsAndGoodwill-IntangibleAssetsDetails" xlink:title="00000042 - Disclosure - Intangible Assets and Goodwill - Intangible Assets (Details)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link: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="loc_us-gaapBusinessAcquisitionAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapBusinessAcquisitionAxis" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_SeriesOfIndividuallyImmaterialBusinessAcquisitionsBMember" xlink:label="loc_ACUSeriesOfIndividuallyImmaterialBusinessAcquisitionsBMember_20"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_SeriesOfIndividuallyImmaterialBusinessAcquisitionsAMember" xlink:label="loc_ACUSeriesOfIndividuallyImmaterialBusinessAcquisitionsAMember_40"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_SeriesOfIndividuallyImmaterialBusinessAcquisitionsCMember" xlink:label="loc_ACUSeriesOfIndividuallyImmaterialBusinessAcquisitionsCMember_60"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember" xlink:label="loc_us-gaapSeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapBusinessAcquisitionAcquireeDomain" xlink:to="loc_us-gaapSeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_80" xlink:type="arc" order="81"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedTradeNamesGross" xlink:label="loc_us-gaapFiniteLivedTradeNamesGross_130"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_FiniteLivedTradeNamesAndCustomerListsGross" xlink:label="loc_ACUFiniteLivedTradeNamesAndCustomerListsGross_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUFiniteLivedTradeNamesAndCustomerListsGross_130" xlink:type="arc" order="2"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedNoncompeteAgreementsGross" xlink:label="loc_us-gaapFiniteLivedNoncompeteAgreementsGross_130"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedLicenseAgreementsGross" xlink:label="loc_us-gaapFiniteLivedLicenseAgreementsGross_130"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedPatentsGross" xlink:label="loc_us-gaapFiniteLivedPatentsGross_130"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedTrademarksGross" xlink:label="loc_us-gaapFiniteLivedTrademarksGross_130"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FiniteLivedCustomerListsGross" xlink:label="loc_us-gaapFiniteLivedCustomerListsGross_130"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaapIntangibleAssetsGrossExcludingGoodwill_130"/>

<link: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="loc_us-gaapFiniteLivedIntangibleAssetsAccumulatedAmortization_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapFiniteLivedIntangibleAssetsAccumulatedAmortization_130" xlink:type="arc" order="9"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaapIntangibleAssetsNetExcludingGoodwill_130"/>

<link: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="loc_us-gaapGoodwill_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapGoodwill_130" xlink:type="arc" order="11"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill" xlink:label="loc_us-gaapIntangibleAssetsNetIncludingGoodwill_130"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/OtherAccruedLiabilitiesDetails" xlink:title="00000043 - Disclosure - Other Accrued Liabilities (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-PlanAssetAllocationDetails" xlink:title="00000044 - Disclosure - Pension and Profit Sharing - Plan Asset Allocation (Details)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:label="loc_us-gaapDefinedBenefitPlanByPlanAssetCategoriesAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapDefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="loc_us-gaapPlanAssetCategoriesDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapDefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:to="loc_us-gaapPlanAssetCategoriesDomain" xlink:type="arc" order="20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapDefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:to="loc_us-gaapPlanAssetCategoriesDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquitySecuritiesMember" xlink:label="loc_us-gaapEquitySecuritiesMember_20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanAssetCategoriesDomain" xlink:to="loc_us-gaapEquitySecuritiesMember_20" xlink:type="arc" order="21"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FixedIncomeFundsMember" xlink:label="loc_us-gaapFixedIncomeFundsMember_40"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanAssetCategoriesDomain" xlink:to="loc_us-gaapFixedIncomeFundsMember_40" xlink:type="arc" order="41"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_OtherSecuritiesInvestmentsMember" xlink:label="loc_ACUOtherSecuritiesInvestmentsMember_60"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanAssetCategoriesDomain" xlink:to="loc_ACUOtherSecuritiesInvestmentsMember_60" xlink:type="arc" order="61"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:label="loc_us-gaapDefinedBenefitPlanWeightedAverageAssetAllocations_90"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapDefinedBenefitPlanWeightedAverageAssetAllocations_90" xlink:type="arc" order="1"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-PensionPlanAssetsByFairValueHiearchyDetails" xlink:title="00000045 - Disclosure - Pension and Profit Sharing - Pension Plan Assets by Fair Value Hiearchy (Details)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaapFairValueByFairValueHierarchyLevelAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" xlink:to="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" order="20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" xlink:to="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaapFairValueInputsLevel1Member_0"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaapFairValueInputsLevel1Member_0" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaapFairValueInputsLevel2Member_10"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaapFairValueInputsLevel3Member_120"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapDefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:type="arc" order="2"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="loc_us-gaapMoneyMarketFundsMember_40"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanAssetCategoriesDomain" xlink:to="loc_us-gaapMoneyMarketFundsMember_40" xlink:type="arc" order="41"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityFundsMember" xlink:label="loc_us-gaapEquityFundsMember_50"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_FixedIncomeFundsAMember" xlink:label="loc_ACUFixedIncomeFundsAMember_150"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanAssetCategoriesDomain" xlink:to="loc_ACUFixedIncomeFundsAMember_150" xlink:type="arc" order="151"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="loc_us-gaapDefinedBenefitPlanFairValueOfPlanAssets_270"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-BenefitObligationDetails" xlink:title="00000046 - Disclosure - Pension and Profit Sharing - Benefit Obligation (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-ChangesInPlanAssetsDetails" xlink:title="00000047 - Disclosure - Pension And Profit Sharing - Changes In Plan Assets (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-PeriodicBenefitCostDetails" xlink:title="00000048 - Disclosure - Pension and Profit Sharing - Periodic Benefit Cost (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-AmountsRecognizedInOtherComprehensiveIncomeDetails" xlink:title="00000049 - Disclosure - Pension and Profit Sharing - Amounts Recognized in Other Comprehensive Income (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharing-EstimatedFutureBenefitPaymentsDetails" xlink:title="00000050 - Disclosure - Pension and Profit Sharing - Estimated Future Benefit Payments (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/PensionAndProfitSharingDetailsNarrative" xlink:title="00000051 - Disclosure - Pension and Profit Sharing (Details Narrative)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxesDetailsNarrative" xlink:title="00000052 - Disclosure - Income Taxes (Details Narrative)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srtStatementGeographicalAxis"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtStatementGeographicalAxis" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srtSegmentGeographicalDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtStatementGeographicalAxis" xlink:to="loc_srtSegmentGeographicalDomain" xlink:type="arc" order="20"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srtSegmentGeographicalDomain_10"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtStatementGeographicalAxis" xlink:to="loc_srtSegmentGeographicalDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_ReportableSegmentsDMember" xlink:label="loc_ACUReportableSegmentsDMember_20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtSegmentGeographicalDomain" xlink:to="loc_ACUReportableSegmentsDMember_20" xlink:type="arc" order="21"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_CanadaMember" xlink:label="loc_ACUCanadaMember_30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ForeignEarningsRepatriated" xlink:label="loc_us-gaapForeignEarningsRepatriated_110"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_UndistributedEarningsOfForeignSubsidiaries" xlink:label="loc_us-gaapUndistributedEarningsOfForeignSubsidiaries_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapUndistributedEarningsOfForeignSubsidiaries_110" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="loc_us-gaapOperatingLossCarryforwards_110"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_ForeignIncomeTaxRate" xlink:label="loc_ACUForeignIncomeTaxRate_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUForeignIncomeTaxRate_110" xlink:type="arc" order="3"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_TaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateUndistributedForeignsTaxRate" xlink:label="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateUndistributedForeignsTaxRate_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateUndistributedForeignsTaxRate_110" xlink:type="arc" order="4"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_TaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateTrasitionTaxRate" xlink:label="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateTrasitionTaxRate_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateTrasitionTaxRate_110" xlink:type="arc" order="5"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_TaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateProvisionalTaxExpenses" xlink:label="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateProvisionalTaxExpenses_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateProvisionalTaxExpenses_110" xlink:type="arc" order="6"/>

<link: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="loc_us-gaapEffectiveIncomeTaxRateContinuingOperations_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapEffectiveIncomeTaxRateContinuingOperations_110" xlink:type="arc" order="7"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_TaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateRecognizedTaxExpense" xlink:label="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateRecognizedTaxExpense_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateRecognizedTaxExpense_110" xlink:type="arc" order="8"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_TaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateTotalTaxExpense" xlink:label="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateTotalTaxExpense_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateTotalTaxExpense_110" xlink:type="arc" order="9"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_TaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateIncreaseInEffectiveTaxRate" xlink:label="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateIncreaseInEffectiveTaxRate_110"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateIncreaseInEffectiveTaxRate_110" xlink:type="arc" order="10"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxes-IncomeTaxExpenseBenefitDetails" xlink:title="00000053 - Disclosure - Income Taxes - Income Tax Expense (Benefit) (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxes-UsAndForeignIncomeBeforeIncomeTaxesDetails" xlink:title="00000054 - Disclosure - Income Taxes - US and Foreign Income Before Income Taxes (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxes-UsStatutoryRateReconciliationDetails" xlink:title="00000055 - Disclosure - Income Taxes - US Statutory Rate Reconciliation (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/IncomeTaxes-DeferredTaxAssetsAndLiabilitiesDetails" xlink:title="00000056 - Disclosure - Income Taxes - Deferred Tax Assets and Liabilities (Details)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/Long-termDebtDetailsNarrative" xlink:title="00000057 - Disclosure - Long-Term Debt (Details Narrative)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaapDebtInstrumentAxis"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaapDebtInstrumentNameDomain"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapDebtInstrumentAxis" xlink:to="loc_us-gaapDebtInstrumentNameDomain" xlink:type="arc" order="20"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaapDebtInstrumentNameDomain_10"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapDebtInstrumentAxis" xlink:to="loc_us-gaapDebtInstrumentNameDomain_10" xlink:type="arc" order="30"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MortgagesMember" xlink:label="loc_us-gaapMortgagesMember_20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDebtInstrumentNameDomain" xlink:to="loc_us-gaapMortgagesMember_20" xlink:type="arc" order="21"/>

<link: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="loc_us-gaapDomesticLineOfCreditMember_50"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDebtInstrumentNameDomain" xlink:to="loc_us-gaapDomesticLineOfCreditMember_50" xlink:type="arc" order="51"/>

<link: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="loc_us-gaapLineOfCreditFacilityMaximumBorrowingCapacity_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapLineOfCreditFacilityMaximumBorrowingCapacity_80" xlink:type="arc" order="0"/>

<link: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="loc_us-gaapDebtInstrumentBasisSpreadOnVariableRate1_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDescription" xlink:label="loc_us-gaapLineOfCreditFacilityInterestRateDescription_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapLineOfCreditFacilityInterestRateDescription_80" xlink:type="arc" order="2"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_LineOfCreditFacilityFeePercentage" xlink:label="loc_ACULineOfCreditFacilityFeePercentage_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACULineOfCreditFacilityFeePercentage_80" xlink:type="arc" order="3"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityExpirationDate1" xlink:label="loc_us-gaapLineOfCreditFacilityExpirationDate1_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaapLineOfCredit_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaapLineOfCreditFacilityRemainingBorrowingCapacity_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapLineOfCreditFacilityRemainingBorrowingCapacity_80" xlink:type="arc" order="6"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentCovenantCompliance" xlink:label="loc_us-gaapDebtInstrumentCovenantCompliance_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACUTaxCutsandJobsActof2017IncompleteAccountingChangeInTaxRateProvisionalTaxExpenses_80" xlink:type="arc" order="8"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaapBusinessCombinationConsiderationTransferred1_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapBusinessCombinationConsiderationTransferred1_80" xlink:type="arc" order="9"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased" xlink:label="loc_us-gaapStockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased_80" xlink:type="arc" order="11"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentPeriodicPayment" xlink:label="loc_us-gaapDebtInstrumentPeriodicPayment_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MaturitiesOfLongTermDebtAbstract" xlink:label="loc_us-gaapMaturitiesOfLongTermDebtAbstract_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_80"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapMaturitiesOfLongTermDebtAbstract_80" xlink:to="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_80" xlink:type="arc" order="14"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_80"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="loc_us-gaapLongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_80"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/CommitmentsAndContingenciesDetailsNarrative" xlink:title="00000058 - Disclosure - Commitments and Contingencies (Details Narrative)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/RevenueFromContractsWithCustomersDetails" xlink:title="00000059 - Disclosure - Revenue from Contracts with Customers (Details)">

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_StatementGeographicalAxis" xlink:label="loc_srtStatementGeographicalAxis"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srtSegmentGeographicalDomain"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_SegmentGeographicalDomain" xlink:label="loc_srtSegmentGeographicalDomain_10"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_UnitedStatesMember" xlink:label="loc_ACUUnitedStatesMember_0"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtSegmentGeographicalDomain" xlink:to="loc_ACUUnitedStatesMember_0" xlink:type="arc" order="1"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_CanadaMember" xlink:label="loc_ACUCanadaMember_10"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_EuropeMember" xlink:label="loc_srtEuropeMember_20"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtSegmentGeographicalDomain" xlink:to="loc_srtEuropeMember_20" xlink:type="arc" order="21"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srtProductOrServiceAxis"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain"/>

<link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/srt/2018/elts/srt-2018-01-31.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain_10"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_ProductAMember" xlink:label="loc_ACUProductAMember_0"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_ACUProductAMember_0" xlink:type="arc" order="2"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_ProductBMember" xlink:label="loc_ACUProductBMember_40"/>

<link:loc xlink:type="locator" xlink:href="acu-20181231.xsd#ACU_RevenuesDisaggregationByCategory" xlink:label="loc_ACURevenuesDisaggregationByCategory_130"/>

<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_ACURevenuesDisaggregationByCategory_130" xlink:type="arc" order="2"/>

</link:definitionLink>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/SegmentInformationDetailsNarrative" xlink:title="00000060 - Disclosure - Segment Information (Details Narrative)"/>

<link:definitionLink xlink:type="extended" xlink:role="http://acu.com/role/SegmentInformation-FinancialDataBySegmentDetails" xlink:title="00000061 - Disclosure - Segment Information - Financial Data by Segment (Details)">