-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 R7YnDxS9CEsDPW7pWs/Lffy4lauvuNu9y3RMVFDKFblojGoswfJfa7rN9I2bV/kH
 m7Tr11rfdxQGEpoCaZJ2eA==

<SEC-DOCUMENT>0001104659-06-023745.txt : 20060407
<SEC-HEADER>0001104659-06-023745.hdr.sgml : 20060407
<ACCEPTANCE-DATETIME>20060407170144
ACCESSION NUMBER:		0001104659-06-023745
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060405
FILED AS OF DATE:		20060407
DATE AS OF CHANGE:		20060407

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MSC INDUSTRIAL DIRECT CO INC
		CENTRAL INDEX KEY:			0001003078
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-INDUSTRIAL MACHINERY & EQUIPMENT [5084]
		IRS NUMBER:				113289165
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			0827

	BUSINESS ADDRESS:	
		STREET 1:		75 MAXESS RD
		CITY:			MELVILLE
		STATE:			NY
		ZIP:			11747
		BUSINESS PHONE:		516-812-2000

	MAIL ADDRESS:	
		STREET 1:		151 SUNNYSIDE BLVD
		CITY:			PLAINVIEW
		STATE:			NY
		ZIP:			11803

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SANDLER DAVID
		CENTRAL INDEX KEY:			0001245882

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14130
		FILM NUMBER:		06748711

	MAIL ADDRESS:	
		STREET 1:		C/O MSC INDUSTRIAL DIRECT CO INC
		STREET 2:		75 MAXESS RD
		CITY:			MELVILLE
		STATE:			NY
		ZIP:			11747
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-04-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001003078</issuerCik>
        <issuerName>MSC INDUSTRIAL DIRECT CO INC</issuerName>
        <issuerTradingSymbol>MSM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001245882</rptOwnerCik>
            <rptOwnerName>SANDLER DAVID</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MSC INDUSTRIAL DIRECT CO INC</rptOwnerStreet1>
            <rptOwnerStreet2>75 MAXESS RD</rptOwnerStreet2>
            <rptOwnerCity>MELVILLE</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11747</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock, $.001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2006-04-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7174</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.9375</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>69018</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock, $.001 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Options (right to buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.9375</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-04-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7174</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-11-09</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7174</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options to Purchase Issuer's Class A common stock, $.001 par value</footnote>
        <footnote id="F2">An option to purchase 125,000 shares of the Issuer's common stock, par value $.001 per share, was issued to the Reporting Person under the Issuer's 1998 Stock Option Plan.  One fifth of such option became exercisable on each of November 9, 2001, November 9, 2002, November 9, 2003, November 9, 2004 and November 9, 2005.</footnote>
        <footnote id="F3">Class A Common Stock, $.001 par value.</footnote>
        <footnote id="F4">Held in trust for the benefit of the Reporting Persons children.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ David Sandler</signatureName>
        <signatureDate>2006-04-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----