<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000095301</issuerCik>
        <issuerName>SEQUA CORP /DE/</issuerName>
        <issuerTradingSymbol>SQAA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001179590</rptOwnerCik>
            <rptOwnerName>WEINSTEIN MARTIN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUA CORP</rptOwnerStreet1>
            <rptOwnerStreet2>200 PARK AVENUE, 44TH FL</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10166</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice Chairman &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>75840</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>175</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1318</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1318</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>175</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee stock option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>41.7</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20204</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>133.3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-09-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20204</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Disposed of pursuant to Agreement and Plan of Merger, dated as of July 8, 2007, by and among Blue Jay Acquisition Corporation, Blue Jay Merger Corporation and Sequa Corporation (the &quot;Merger Agreement&quot;).</footnote>
        <footnote id="F2">Shares held in the Sequa 401(k) Plan; disposed of pursuant to the Merger Agreement.</footnote>
        <footnote id="F3">The option, which provided vesting in 3 equal annual installments beginning 09/25/2004, was cancelled pursuant to the Merger Agreement in exchange for a cash payment representing the difference between the exercise price of the option and the exchange price of the stock under the Merger Agreement of $175 per share.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Martin Weinstein</signatureName>
        <signatureDate>2007-12-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2007-12-03
0
0000095301
SEQUA CORP /DE/
SQAA
0001179590
WEINSTEIN MARTIN
C/O SEQUA CORP
200 PARK AVENUE, 44TH FL
NEW YORK
NY
10166
1
1
0
0
Vice Chairman & CEO
Class A Common
2007-12-03
4
D
0
75840
175
D
1318
D
Class A Common
2007-12-03
4
D
0
1318
175
D
0
D
Employee stock option (right to buy)
41.7
2007-12-03
4
D
0
20204
133.3
D
2008-09-25
Class A Common
20204
0
D
Disposed of pursuant to Agreement and Plan of Merger, dated as of July 8, 2007, by and among Blue Jay Acquisition Corporation, Blue Jay Merger Corporation and Sequa Corporation (the "Merger Agreement").
Shares held in the Sequa 401(k) Plan; disposed of pursuant to the Merger Agreement.
The option, which provided vesting in 3 equal annual installments beginning 09/25/2004, was cancelled pursuant to the Merger Agreement in exchange for a cash payment representing the difference between the exercise price of the option and the exchange price of the stock under the Merger Agreement of $175 per share.
/s/Martin Weinstein
2007-12-04