<SEC-DOCUMENT>0001191458-17-000005.txt : 20170725
<SEC-HEADER>0001191458-17-000005.hdr.sgml : 20170725
<ACCEPTANCE-DATETIME>20170725165547
ACCESSION NUMBER:		0001191458-17-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170724
FILED AS OF DATE:		20170725
DATE AS OF CHANGE:		20170725

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KRAMER FRANCIS J
		CENTRAL INDEX KEY:			0001191458

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16195
		FILM NUMBER:		17980907

	MAIL ADDRESS:	
		STREET 1:		C/O II-VI INCORPORATED
		STREET 2:		375 SAXONBURG BLVD
		CITY:			SAXONBURG
		STATE:			PA
		ZIP:			16056

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			II-VI INC
		CENTRAL INDEX KEY:			0000820318
		STANDARD INDUSTRIAL CLASSIFICATION:	OPTICAL INSTRUMENTS & LENSES [3827]
		IRS NUMBER:				251214948
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		375 SAXONBURG BLVD
		CITY:			SAXONBURG
		STATE:			PA
		ZIP:			16056
		BUSINESS PHONE:		724-352-4455

	MAIL ADDRESS:	
		STREET 1:		375 SAXONBURG BLVD
		CITY:			SAXONBURG
		STATE:			PA
		ZIP:			16056
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-07-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000820318</issuerCik>
        <issuerName>II-VI INC</issuerName>
        <issuerTradingSymbol>IIVI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001191458</rptOwnerCik>
            <rptOwnerName>KRAMER FRANCIS J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O II-VI INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>375 SAXONBURG BLVD</rptOwnerStreet2>
            <rptOwnerCity>SAXONBURG</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>16056</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-07-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>40</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>329827</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>285401</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spousal Limited Access Trust</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sale transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 13, 2017.</footnote>
        <footnote id="F2">The total amount of securities beneficially owned has been adjusted to reflect beneficial ownership of 1,000 additional shares that were inadvertently omitted in the amount of securities beneficially owned by the reporting person following the transactions reported in the Form 4 for the reporting person filed on June 21, 2017.</footnote>
        <footnote id="F3">The reporting person disclaims beneficial ownership of these securities, other than to the extent of the reporting person's pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jeffrey W. Acre, Attorney-in-Fact</signatureName>
        <signatureDate>2016-07-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
