<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-07-07</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001015725</rptOwnerCik>
            <rptOwnerName>ALEXANDER NORMAN E/</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, Chief Exec. Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Class A Common</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-07</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>J</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>125385</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
                <footnoteId id="F1"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>125385</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Class A Common</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-07</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>J</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>125385</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
                <footnoteId id="F2"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>2038849</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>See footnote 3</value>
                <footnoteId id="F3"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Class B Common</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-07</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>J</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>198886</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
                <footnoteId id="F4"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>198886</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Class B Common</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-07</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>J</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>198886</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
                <footnoteId id="F5"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>1745858</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>See footnote 6</value>
                <footnoteId id="F6"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Shares transferred from a trust of which Mr. Alexander, his wife and his estate and/or issue are beneficiaries (the &quot;Trust&quot;).</footnote>
        <footnote id="F2">See footnote number 1.</footnote>
        <footnote id="F3">Indirect owndership in Class A Common Stock:   110,415 shares  held in the Norman E. Alexander Family Foundation;  1,926,355 shares owned by Fifty Broad Street, Inc., Forfed Corporation, YOUANDI Corp., 42 New Street, Inc. and Galleon Syndicate Corporation, all of which are controlled by Mr. Alexander; and 2,079 shares held in the Sequa 401(k) Plan for Mr. Alexander's account and were acquired at various prices through June 2003.</footnote>
        <footnote id="F4">See footnote number 1.</footnote>
        <footnote id="F5">See footnote number 1.</footnote>
        <footnote id="F6">Indirect ownership in Class B Common Stock: 148,552 shares owned by the Trust and 1,597,306 shares owned by Fifty Broad Street, Inc., Forfed Corporation, YOUANDI Corp., 42 New Street, Inc. and Galleon Syndicate Corporation, all of which are controlled by Mr. Alexander.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Norman E. Alexander</signatureName>
        <signatureDate>2003-07-09</signatureDate>
    </ownerSignature>

</ownershipDocument>
[{"type": "4", "sequence": "1", "filename": "primary_doc.xml", "description": "PRIMARY DOCUMENT", "secsgml_size_bytes": 8180}]
4
2003-07-07
0
0000095301
SEQUA CORP /DE/
SQAA SQAB
0001015725
ALEXANDER NORMAN E/
1
1
1
0
Chairman, Chief Exec. Officer
Class A Common
2003-07-07
4
J
0
125385
0
A
125385
D
Class A Common
2003-07-07
4
J
0
125385
0
D
2038849
I
See footnote 3
Class B Common
2003-07-07
4
J
0
198886
0
A
198886
D
Class B Common
2003-07-07
4
J
0
198886
0
D
1745858
I
See footnote 6
Shares transferred from a trust of which Mr. Alexander, his wife and his estate and/or issue are beneficiaries (the "Trust").
See footnote number 1.
Indirect owndership in Class A Common Stock:   110,415 shares  held in the Norman E. Alexander Family Foundation;  1,926,355 shares owned by Fifty Broad Street, Inc., Forfed Corporation, YOUANDI Corp., 42 New Street, Inc. and Galleon Syndicate Corporation, all of which are controlled by Mr. Alexander; and 2,079 shares held in the Sequa 401(k) Plan for Mr. Alexander's account and were acquired at various prices through June 2003.
See footnote number 1.
See footnote number 1.
Indirect ownership in Class B Common Stock: 148,552 shares owned by the Trust and 1,597,306 shares owned by Fifty Broad Street, Inc., Forfed Corporation, YOUANDI Corp., 42 New Street, Inc. and Galleon Syndicate Corporation, all of which are controlled by Mr. Alexander.
/s/ Norman E. Alexander
2003-07-09