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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001140361-11-000900.txt : 20110104
<SEC-HEADER>0001140361-11-000900.hdr.sgml : 20110104
<ACCEPTANCE-DATETIME>20110104170715
ACCESSION NUMBER:		0001140361-11-000900
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110101
FILED AS OF DATE:		20110104
DATE AS OF CHANGE:		20110104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SULLIVAN JOHN L III
		CENTRAL INDEX KEY:			0001187212

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-00599
		FILM NUMBER:		11507049

	MAIL ADDRESS:	
		STREET 1:		13 CEDAR DRIVE
		CITY:			CROMWELL
		STATE:			CT
		ZIP:			06416

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EASTERN CO
		CENTRAL INDEX KEY:			0000031107
		STANDARD INDUSTRIAL CLASSIFICATION:	CUTLERY, HANDTOOLS & GENERAL HARDWARE [3420]
		IRS NUMBER:				060330020
		STATE OF INCORPORATION:			CT
		FISCAL YEAR END:			0102

	BUSINESS ADDRESS:	
		STREET 1:		112 BRIDGE ST
		STREET 2:		P O BOX 460
		CITY:			NAUGATUCK
		STATE:			CT
		ZIP:			06770
		BUSINESS PHONE:		2037292255

	MAIL ADDRESS:	
		STREET 1:		112 BRIDGE STREET
		STREET 2:		P O BOX 460
		CITY:			NAUGATUCK
		STATE:			CT
		ZIP:			06770
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 5
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2011-01-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000031107</issuerCik>
        <issuerName>EASTERN CO</issuerName>
        <issuerTradingSymbol>EML</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001187212</rptOwnerCik>
            <rptOwnerName>SULLIVAN JOHN L III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>112 BRIDGE STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NAUGATUCK</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06770</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President &amp; CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2010-12-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>801</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>31411</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Qualified employee stock option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.60</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2001-04-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2011-04-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">801 shares acquired at various prices for the period 6/2/10 through 12/15/2010 under The Eastern Company Dividend Reinvestment Plan and The Eastern Company Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">The original 4/26/2001 option was for 15,000 shares at $14.40 per share. 5,800 shares were vested on 1/1/2004; 6,944 shares were vested on 1/1/2005; and the remaining 2,256 shares were vested on 1/1/2006. As a result of a 3-for-2 stock split effective 10/18/2006 this option is now for 22,500 shares at $9.60 per share. On October 28, 2010 1,000 shares were exercised, on November 4, 2010 2,000 shares were exercised, on November 9, 2010 4,000 shares were exercised and on December 1, 2010 7,500 shares were exercised at $9.60 per share, leaving a balance of 8,000 shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/John L. Sullivan III</signatureName>
        <signatureDate>2011-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
