-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 LGzHdMFTxE2D+Q85w/Hux44HQ+Hs3ByZgxNtmS6UoZsDc1B8GG5Bmy6gYOSndAKQ
 crUuZVtxqua7Xr35a7n1hA==

<SEC-DOCUMENT>0001140361-07-009026.txt : 20070503
<SEC-HEADER>0001140361-07-009026.hdr.sgml : 20070503
<ACCEPTANCE-DATETIME>20070503161330
ACCESSION NUMBER:		0001140361-07-009026
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070501
FILED AS OF DATE:		20070503
DATE AS OF CHANGE:		20070503

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
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07283
		FILM NUMBER:		07815724

	BUSINESS ADDRESS:	
		STREET 1:		3050 SPRUCE STREET
		CITY:			ST LOUIS
		STATE:			MO
		ZIP:			63103
		BUSINESS PHONE:		618-624-8188

	MAIL ADDRESS:	
		STREET 1:		1102 TIMBER RUN
		CITY:			O'FALLON
		STATE:			IL
		ZIP:			62269
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-05-01</periodOfReport>

    <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>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-05-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>750</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>SAR's</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>44.12</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-05-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>44.12</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-05-01</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-05-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>SAR's</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Granted as stock-settled Stock Appreciation Rights (SAR's), which vest equally over a five year period and will be fully vested on 5/1/12.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Terry R. Colvin</signatureName>
        <signatureDate>2007-05-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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