-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 S3CaDx24dTccg6nXcqm21T1FNGfsZnofhSDsWJIQUtanTcQKocVfzOVl9Vatkb6U
 KLU+S5TJMCdVwOg5yAXXFA==

<SEC-DOCUMENT>0001187819-03-000001.txt : 20030723
<SEC-HEADER>0001187819-03-000001.hdr.sgml : 20030723
<ACCEPTANCE-DATETIME>20030723130157
ACCESSION NUMBER:		0001187819-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030722
FILED AS OF DATE:		20030723

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IDEX CORP /DE/
		CENTRAL INDEX KEY:			0000832101
		STANDARD INDUSTRIAL CLASSIFICATION:	PUMPS & PUMPING EQUIPMENT [3561]
		IRS NUMBER:				363555336
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		630 DUNDEE RD STE 400
		CITY:			NORTHBROOK
		STATE:			IL
		ZIP:			60062
		BUSINESS PHONE:		8474987070

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MCMURRAY JOHN L
		CENTRAL INDEX KEY:			0001187819

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10235
		FILM NUMBER:		03797853

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		847 498 7070

	MAIL ADDRESS:	
		STREET 1:		C/O IDEX CORP
		STREET 2:		630 DUNDEE ROAD
		CITY:			NORTHBROOK
		STATE:			IL
		ZIP:			60062
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-07-22</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000832101</issuerCik>
        <issuerName>IDEX CORP /DE/</issuerName>
        <issuerTradingSymbol>IEX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001187819</rptOwnerCik>
            <rptOwnerName>MCMURRAY JOHN L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP - Operational Excellence</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>COMMON STOCK</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-22</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>2925</value>
            </transactionShares>
            <transactionValue>
                <value>16.278</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>3628</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>COMMON STOCK</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-22</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>2925</value>
            </transactionShares>
            <transactionValue>
                <value>37.0825</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>703</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>OPTIONS (RIGHT TO BUY)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>16.278</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-07-22</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>2925</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>1999-04-26</value>
        </exerciseDate>
        <expirationDate>
            <value>2004-04-26</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>COMMON STOCK</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>2925</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>112250</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>


    <ownerSignature>
        <signatureName>JOHN L. MCMURRAY</signatureName>
        <signatureDate>2003-07-23</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----