<SEC-DOCUMENT>0001026608-19-000016.txt : 20190423
<SEC-HEADER>0001026608-19-000016.hdr.sgml : 20190423
<ACCEPTANCE-DATETIME>20190423172244
ACCESSION NUMBER:		0001026608-19-000016
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190422
FILED AS OF DATE:		20190423
DATE AS OF CHANGE:		20190423

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BARKER BRIAN
		CENTRAL INDEX KEY:			0001774022

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07698
		FILM NUMBER:		19762217

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

ISSUER:		

	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

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-04-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000002098</issuerCik>
        <issuerName>ACME UNITED CORP</issuerName>
        <issuerTradingSymbol>ACU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001774022</rptOwnerCik>
            <rptOwnerName>BARKER BRIAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>55 WALLS DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FAIRFIELD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06824</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>21.2</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-04-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>21.2</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2029-04-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1,000 shares will vest on April 22, 2019, 1,000 shares will vest on April 22, 2020, 1,000 shares will vest on April 22, 2021 and 1,000 shares will vest on April 22, 2022</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Brian Barker</signatureName>
        <signatureDate>2019-04-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
