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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001179110-09-005339.txt : 20090318
<SEC-HEADER>0001179110-09-005339.hdr.sgml : 20090318
<ACCEPTANCE-DATETIME>20090318182621
ACCESSION NUMBER:		0001179110-09-005339
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090311
FILED AS OF DATE:		20090318
DATE AS OF CHANGE:		20090318

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Wathen David M
		CENTRAL INDEX KEY:			0001326561

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10716
		FILM NUMBER:		09691917

	MAIL ADDRESS:	
		STREET 1:		5155 INKSTER ROAD
		CITY:			BLOOMFIELD HILLS
		STATE:			MI
		ZIP:			48302

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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-03-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001326561</rptOwnerCik>
            <rptOwnerName>Wathen David M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>39400 WOODWARD AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 130</rptOwnerStreet2>
            <rptOwnerCity>BLOOMFIELD HILLS</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>48304</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>14600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.59</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>98600</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.63</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>105000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">David M. Wathen and Laurene A. Wathen JT TEN WROS</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price.  These shares were purchased in multiple transactions at prices ranging from $1.59 to $1.65, inclusive.  The reporting person undertakes to provide to TriMas Corporation, any security holder of TriMas Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2)to this Form 4.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Paula Reno attorney-in-fact</signatureName>
        <signatureDate>2009-03-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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