ShadowBuys

SEC EDGAR · Insider purchase

MSM: Slone Reuben E reported buying shares

2 reported purchases of non-derivative securities. Code P includes open-market and private purchases; it does not establish motive.

Follow MSM
Became public
Oct 23, 2026
Event / period date
Oct 23, 2026
Collected
Nov 8, 2026, 7:17 PM EST

Why this is connected

This filing identifies MSC INDUSTRIAL DIRECT CO INC as the issuer of the security. The company's SEC identifier connects it to MSM.

Reported transactions

Slone Reuben E (Director)

370 shares · Class A Common Stock, $0.001 par value

Oct 23, 2026 · $115.645 per share

63 shares · Class A Common Stock, $0.001 par value

Oct 23, 2026 · $116.5161 per share

Value calculated from the reported shares and prices: $50,129.16.

Code P covers open-market and private purchases. Grants, option exercises, and tax withholding are excluded from purchase results. Read the source footnotes for ownership and pricing details.

Source evidence

Read the source excerpt or record
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-10-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001518692</rptOwnerCik>
            <rptOwnerName>Slone Reuben E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O MSC INDUSTRIAL DIRECT CO., INC.</rptOwnerStreet1>
            <rptOwnerStreet2>515 BROADHOLLOW ROAD</rptOwnerStreet2>
            <rptOwnerCity>MELVILLE</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11747</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock, $0.001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2026-10-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>370</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>115.645</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>370</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock, $0.001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2026-10-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>63</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>116.5161</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>433</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Reuben E. Slone</signatureName>
        <signatureDate>2026-10-23</signatureDate>
    </ownerSignature>
</ownershipDocument>

Congressional trading in MSM

These disclosures provide context. Their presence does not establish a link between a trader and the event.

Original documents control. Public records can be amended, and company connections may require interpretation. Nothing here is investment advice.