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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001104659-10-055693.txt : 20101103
<SEC-HEADER>0001104659-10-055693.hdr.sgml : 20101103
<ACCEPTANCE-DATETIME>20101103204137
ACCESSION NUMBER:		0001104659-10-055693
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101101
FILED AS OF DATE:		20101103
DATE AS OF CHANGE:		20101103

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TRIMAS CORP
		CENTRAL INDEX KEY:			0000842633
		STANDARD INDUSTRIAL CLASSIFICATION:	METAL FORGING & STAMPINGS [3460]
		IRS NUMBER:				382687639
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		39400 WOODWARD AVENUE, SUITE 130
		CITY:			BLOOMFIELD HILLS
		STATE:			MI
		ZIP:			48304
		BUSINESS PHONE:		2486315400

	MAIL ADDRESS:	
		STREET 1:		39400 WOODWARD AVENUE, SUITE 130
		CITY:			BLOOMFIELD HILLS
		STATE:			MI
		ZIP:			48304

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HEARTLAND INDUSTRIAL ASSOCIATES LLC
		CENTRAL INDEX KEY:			0001179822
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10716
		FILM NUMBER:		101162938

	BUSINESS ADDRESS:	
		STREET 1:		55 RAILROAD AVENUE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		2038612622

	MAIL ADDRESS:	
		STREET 1:		55 RAILROAD AVENUE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-11-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000842633</issuerCik>
        <issuerName>TRIMAS CORP</issuerName>
        <issuerTradingSymbol>TRS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001179822</rptOwnerCik>
            <rptOwnerName>HEARTLAND INDUSTRIAL ASSOCIATES LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>177 BROAD STREET</rptOwnerStreet1>
            <rptOwnerStreet2>10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>STAMFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06901</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-11-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3000000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11904972</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities are owned directly by TriMas Investment Fund I, L.L.C. (&quot;TIF I&quot;) and HIP Investment Holdings I, LLC (&quot;HIP Holdings&quot;).  TIF I and HIP Holdings will sell 1,133,024 shares and 1,866,976 shares, respectively, as holders of record of such shares.  Following the sale of these securities, TIF I will own 8,609,206 shares and HIP Holdings will no longer own any shares.  Heartland Industrial Partners, L.P. (&quot;Heartland Partners&quot;), as the managing member of TIF I and HIP Holdings, and Heartland Industrial Associates, L.L.C. (&quot;Heartland&quot;), as the General Partner of Heartland Partners, may each be deemed to be an indirect beneficial owner of the securities held by TIF I and HIP Holdings.  Following the sale of the securities, Heartland Partners will indirectly beneficially own 10,853,033 shares.  Heartland and Heartland Partners each disclaims beneficial ownership (as defined in Rule 16a-1(a)(2)) of these securities, except to the extent of
 its pecuniary interest therein.</footnote>
        <footnote id="F2">Heartland, Heartland Partners, TIF I and HIP Holdings may be deemed to be members of a group for purposes of Section 13(d) of the Securities Exchange Act of 1934.</footnote>
    </footnotes>

    <remarks>Signature by Daniel P. Tredwell, as Managing Member of Heartland, which is General Partner of Heartland Partners, which is managing member of TIF I and HIP Holdings.</remarks>

    <ownerSignature>
        <signatureName>/s/ Daniel P. Tredwell</signatureName>
        <signatureDate>2010-11-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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