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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-12-15</periodOfReport>

    <issuer>
        <issuerCik>0000054381</issuerCik>
        <issuerName>KAMAN CORP</issuerName>
        <issuerTradingSymbol>KAMN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001330607</rptOwnerCik>
            <rptOwnerName>Minnich George E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/ KAMAN CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>1332 BLUE HILLS AVE</rptOwnerStreet2>
            <rptOwnerCity>BLOOMFIELD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Kaman Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.0861</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This figure represents the weighted average purchase price for the shares purchased. The range of prices was $24.0765 to $24.10. The reporting person will provide full information regarding the number of shares purchased at each separate price upon request by the SEC staff, the issuer, or any security holder of the issuer</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Candace A. Clark, Power of Attorney for Mr. Minnich</signatureName>
        <signatureDate>2009-12-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
