    <SEC-DOCUMENT>0001564590-21-019268-index.html : 20210419
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    <ACCEPTANCE-DATETIME>20210419092645
    ACCESSION NUMBER:		0001564590-21-019268
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		15
    CONFORMED PERIOD OF REPORT:	20210419
    ITEM INFORMATION:		Results of Operations and Financial Condition
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20210419
    DATE AS OF CHANGE:		20210419

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			ACME UNITED CORP
    		CENTRAL INDEX KEY:			0000002098
    		STANDARD INDUSTRIAL CLASSIFICATION:	CUTLERY, HANDTOOLS & GENERAL HARDWARE [3420]
    		IRS NUMBER:				060236700
    		STATE OF INCORPORATION:			CT
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-07698
    		FILM NUMBER:		21833462

    	BUSINESS ADDRESS:
    		STREET 1:		55 WALLS DRIVE
    		CITY:			FAIRFIELD
    		STATE:			CT
    		ZIP:			06824
    		BUSINESS PHONE:		203-254-6060

    	MAIL ADDRESS:
    		STREET 1:		55 WALLS DRIVE
    		CITY:			FAIRFIELD
    		STATE:			CT
    		ZIP:			06824

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	ACME SHEAR CO
    		DATE OF NAME CHANGE:	19710713
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    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>acu-8k_20210419.htm
    <DESCRIPTION>8-K Q1 2021
    <TEXT>
    Document 1 - file: acu-8k_20210419.htm

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    <SEQUENCE>2
    <FILENAME>acu-ex991_6.htm
    <DESCRIPTION>EX-99.1
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    <FILENAME>acu-20210419.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA
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    <SEQUENCE>6
    <FILENAME>acu-20210419_lab.xml
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    <TYPE>EX-101.PRE
    <SEQUENCE>7
    <FILENAME>acu-20210419_pre.xml
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    <FILENAME>acu-8k_20210419_htm.xml
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    <TYPE>EXCEL
    <SEQUENCE>10
    <FILENAME>Financial_Report.xlsx
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    <TEXT>
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    <SEQUENCE>11
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    <TEXT>
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    <SEQUENCE>12
    <FILENAME>report.css
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    <TEXT>
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    <TYPE>XML
    <SEQUENCE>13
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    <TYPE>JSON
    <SEQUENCE>15
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    <SEQUENCE>16
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