<SEC-DOCUMENT>0000082811-13-000067.txt : 20130524
<SEC-HEADER>0000082811-13-000067.hdr.sgml : 20130524
<ACCEPTANCE-DATETIME>20130524155117
ACCESSION NUMBER:		0000082811-13-000067
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20130502
FILED AS OF DATE:		20130524
DATE AS OF CHANGE:		20130524

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			REGAL BELOIT CORP
		CENTRAL INDEX KEY:			0000082811
		STANDARD INDUSTRIAL CLASSIFICATION:	MOTORS & GENERATORS [3621]
		IRS NUMBER:				390875718
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 STATE ST
		CITY:			BELOIT
		STATE:			WI
		ZIP:			53511
		BUSINESS PHONE:		6083648800

	MAIL ADDRESS:	
		STREET 1:		200 STATE STREET
		CITY:			BELOIT
		STATE:			WI
		ZIP:			53511-6254

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BELOIT TOOL CORP
		DATE OF NAME CHANGE:	19730522

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RECORD A PUNCH CORP
		DATE OF NAME CHANGE:	19690320

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COLVIN TERRY R
		CENTRAL INDEX KEY:			0001201796

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07283
		FILM NUMBER:		13872013

	MAIL ADDRESS:	
		STREET 1:		1102 TIMBER RUN
		CITY:			O'FALLON
		STATE:			IL
		ZIP:			62269
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>wf-form4a_136942506668380.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2013-05-02</periodOfReport>

    <dateOfOriginalSubmission>2013-05-06</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000082811</issuerCik>
        <issuerName>REGAL BELOIT CORP</issuerName>
        <issuerTradingSymbol>RBC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001201796</rptOwnerCik>
            <rptOwnerName>COLVIN TERRY R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6771 WHITE OAK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTH BELOIT</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>61080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP/Human Resources</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Appreciation Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>64.99</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2013-05-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5125</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2015-05-02</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2023-05-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5125.0</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5125</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This amended Form 4 is being filed to correct an error in the calculation of the number of Stock Appreciation Rights awarded to the reporting person on 5-2-2013. The original Form 4 filed on 5-6-2013 reported 4,200 SARs awarded.</footnote>
        <footnote id="F2">Granted as stock-settled SARs under the 2013 Equity Incentive Plan. The SARs vest and become exercisable 40% on the second anniversary of the date of the grant, 60% on the third anniversary of the date of the grant, 80% on the fourth anniversary of the date of the grant and 100% on the fifth anniversary of the date of the grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Peter C. Underwood as Power of Attorney</signatureName>
        <signatureDate>2013-05-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
