<SEC-DOCUMENT>0000720500-16-000113.txt : 20161118
<SEC-HEADER>0000720500-16-000113.hdr.sgml : 20161118
<ACCEPTANCE-DATETIME>20161118185347
ACCESSION NUMBER:		0000720500-16-000113
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20161110
FILED AS OF DATE:		20161118
DATE AS OF CHANGE:		20161118

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMTECH SYSTEMS INC
		CENTRAL INDEX KEY:			0000720500
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				860411215
		STATE OF INCORPORATION:			AZ
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		131 S CLARK DR
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281
		BUSINESS PHONE:		6029675146

	MAIL ADDRESS:	
		STREET 1:		131 SOUTH CLARK DRIVE
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	QUARTZ ENGINEERING & MATERIALS INC
		DATE OF NAME CHANGE:	19870715

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HASS ROBERT T
		CENTRAL INDEX KEY:			0001266457

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-11412
		FILM NUMBER:		162008832

	MAIL ADDRESS:	
		STREET 1:		C/O AMTECH SYSTEMS INC
		STREET 2:		131 SOUTH CLARK DRIVE
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_147951321508741.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-11-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000720500</issuerCik>
        <issuerName>AMTECH SYSTEMS INC</issuerName>
        <issuerTradingSymbol>ASYS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001266457</rptOwnerCik>
            <rptOwnerName>HASS ROBERT T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AMTECH SYSTEMS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>131 SOUTH CLARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>TEMPE</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85281</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Amtech Systems, Inc. $.01 par value common stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.71</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-11-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-11-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">One-fourth of the stock option granted vest on each of the first four anniversaries of the grant date.</footnote>
        <footnote id="F2">Price omitted because the transaction is a grant of a stock option.</footnote>
        <footnote id="F3">This is the number of derivative securities, with the same terms and conditions, following the reported transaction. Total of all derivative securities, with different terms and conditions, held following the reported transaction is 49,384.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Robert T Hass</signatureName>
        <signatureDate>2016-11-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
