-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Ntftt40V+NRdfGKHJG0WAsFagHAxrLHbiStwdpv53anWdSc06fg8JUfnNPaEoca8
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<SEC-DOCUMENT>0001312548-07-000051.txt : 20071002
<SEC-HEADER>0001312548-07-000051.hdr.sgml : 20071002
<ACCEPTANCE-DATETIME>20071002170801
ACCESSION NUMBER:		0001312548-07-000051
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070921
FILED AS OF DATE:		20071002
DATE AS OF CHANGE:		20071002

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Murphy Michael R
		CENTRAL INDEX KEY:			0001323510

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13797
		FILM NUMBER:		071150712

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(312) 265-9600

	MAIL ADDRESS:	
		STREET 1:		C/O DISCOVERY GROUP I, LLC
		STREET 2:		191 N. WACKER DRIVE SUITE 1685
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Donoghue Daniel J
		CENTRAL INDEX KEY:			0001323511

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13797
		FILM NUMBER:		071150713

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(312) 265-9600

	MAIL ADDRESS:	
		STREET 1:		C/O DISCOVERY GROUP I, LLC
		STREET 2:		191 N. WACKER DRIVE SUITE 1685
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HAWK CORP
		CENTRAL INDEX KEY:			0000849240
		STANDARD INDUSTRIAL CLASSIFICATION:	AIRCRAFT PART & AUXILIARY EQUIPMENT, NEC [3728]
		IRS NUMBER:				341608156
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 PUBLIC SQ.
		STREET 2:		STE 1500
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114
		BUSINESS PHONE:		2168613553

	MAIL ADDRESS:	
		STREET 1:		200 PUBLIC SQUARE
		STREET 2:		STE 1500
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114-2301

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HAWK GROUP OF COMPANIES INC
		DATE OF NAME CHANGE:	19950417

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Discovery Group I, LLC
		CENTRAL INDEX KEY:			0001312548
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13797
		FILM NUMBER:		071150714

	BUSINESS ADDRESS:	
		STREET 1:		191 N. WACKER DRIVE SUITE 1685
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		(312) 265-96000

	MAIL ADDRESS:	
		STREET 1:		191 N. WACKER DRIVE SUITE 1685
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-09-21</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000849240</issuerCik>
        <issuerName>HAWK CORP</issuerName>
        <issuerTradingSymbol>HWK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001312548</rptOwnerCik>
            <rptOwnerName>Discovery Group I, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>191 N. WACKER DRIVE SUITE 1685</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001323511</rptOwnerCik>
            <rptOwnerName>Donoghue Daniel J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DISCOVERY GROUP I, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>191 N. WACKER DRIVE SUITE 1685</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001323510</rptOwnerCik>
            <rptOwnerName>Murphy Michael R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DISCOVERY GROUP I, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>191 N. WACKER DRIVE SUITE 1685</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>791399</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Discovery Equity Partners, L.P.</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>132059</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Pleiades Investment Partners - D, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Discovery Group I, LLC is the General Partner of Discovery Equity Partners, L.P., which is a discretionary client of the reporting person, that owns the reported securities. The reporting person disclaims beneficial ownership of the reported securities except to the extent of its pecuniary interest therein.</footnote>
        <footnote id="F2">Discovery Group I, LLC is an investment manager for Pleiades Investment Partners - D, L.P., which is a discretionary client of the reporting person, that owns the reported securities. The reporting person disclaims beneficial ownership of the reported securities except to the extent of its pecuniary interest therein.</footnote>
    </footnotes>

    <remarks>Michael R. Murphy and Daniel J. Donoghue are managing members of Discovery Group I, LLC, and each disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein.</remarks>

    <ownerSignature>
        <signatureName>Michael R. Murphy, Managing Director</signatureName>
        <signatureDate>2007-10-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Daniel J. Donoghue</signatureName>
        <signatureDate>2007-10-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Michael R. Murphy</signatureName>
        <signatureDate>2007-10-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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