<SEC-DOCUMENT>0001191458-17-000007.txt : 20170821
<SEC-HEADER>0001191458-17-000007.hdr.sgml : 20170821
<ACCEPTANCE-DATETIME>20170821143249
ACCESSION NUMBER:		0001191458-17-000007
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170818
FILED AS OF DATE:		20170821
DATE AS OF CHANGE:		20170821

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:		171042910

	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>2017-08-18</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>2017-08-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2280</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>359066</value>
                </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="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>35.25</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-08-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-08-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5700</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5700</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares represent a restricted stock award granted to the reporting person pursuant to the II-VI Incorporated Amended and Restated 2012 Omnibus Incentive Plan.  The award will vest in three equal annual installments beginning on August 18, 2018.</footnote>
        <footnote id="F2">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>
        <footnote id="F3">These options will vest in four equal annual installments beginning on August 18, 2018.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jeffrey W. Acre, Attorney-in-Fact</signatureName>
        <signatureDate>2017-08-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
