<SEC-DOCUMENT>0000842633-15-000127.txt : 20150914
<SEC-HEADER>0000842633-15-000127.hdr.sgml : 20150914
<ACCEPTANCE-DATETIME>20150914131521
ACCESSION NUMBER:		0000842633-15-000127
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150910
FILED AS OF DATE:		20150914
DATE AS OF CHANGE:		20150914

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:			Hindman Colin E
		CENTRAL INDEX KEY:			0001629498

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10716
		FILM NUMBER:		151105155

	MAIL ADDRESS:	
		STREET 1:		39400 WOODWARD AVENUE
		STREET 2:		STE. 130
		CITY:			BLOOMFIELD HILLS
		STATE:			MI
		ZIP:			48304
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_144225091139024.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-09-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001629498</rptOwnerCik>
            <rptOwnerName>Hindman Colin E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>39400 WOODWARD AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>STE. 130</rptOwnerStreet2>
            <rptOwnerCity>BLOOMFIELD HILLS</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48304</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President Human Resources</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25745</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-09-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>459</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26204</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Includes shares of Issuer common stock underlying restricted stock units.  In connection with the spin-off of Horizon Global Corporation by the Issuer on June 30, 2015 such equity awards were adjusted to generally preserve the value of the original award as of June 30, 2015.  Such amount of shares is estimated as of June 30, 2015 based on preliminary information regarding the spin-off.  Final amounts, if different, will be reported in a subsequent filing.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Joshua A. Sherbin attorney-in-fact</signatureName>
        <signatureDate>2015-09-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
