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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-01-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000928391</rptOwnerCik>
            <rptOwnerName>SULLIVAN FRED R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SEQUA CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>200 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10166</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common</value>
            </securityTitle>
            <transactionDate>
                <value>2005-01-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>646</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>61.91</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6333</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1209</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by wife</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares are issued to Mr. Sullivan pursuant to the Sequa Corporation Directors' Stock Compensation Plan (the &quot;Plan&quot;).  The shares are restricted from disposition or transfer in accorndance with the provisions set forth in the Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Diane C. Bunt, as attorney-in-fact</signatureName>
        <signatureDate>2005-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2005-01-01
0
0000095301
SEQUA CORP /DE/
SQAA
0000928391
SULLIVAN FRED R
C/O SEQUA CORPORATION
200 PARK AVENUE
NEW YORK
NY
10166
1
0
0
0
Class A Common
2005-01-01
4
A
0
646
61.91
A
6333
D
Class A Common
1209
I
by wife
These shares are issued to Mr. Sullivan pursuant to the Sequa Corporation Directors' Stock Compensation Plan (the "Plan").  The shares are restricted from disposition or transfer in accorndance with the provisions set forth in the Plan.
/s/Diane C. Bunt, as attorney-in-fact
2005-01-04