<SEC-DOCUMENT>0000720500-18-000003.txt : 20180112
<SEC-HEADER>0000720500-18-000003.hdr.sgml : 20180112
<ACCEPTANCE-DATETIME>20180112162131
ACCESSION NUMBER:		0000720500-18-000003
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180104
FILED AS OF DATE:		20180112
DATE AS OF CHANGE:		20180112

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WHANG MICHAEL
		CENTRAL INDEX KEY:			0001727924

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-11412
		FILM NUMBER:		18526196

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

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 SOUTH CLARK DRIVE
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281
		BUSINESS PHONE:		4809675146

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_151579207708214.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2018-01-04</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001727924</rptOwnerCik>
            <rptOwnerName>WHANG MICHAEL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AMTECH SYSTEMS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>131 S 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>Vice President of Operations</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Amtech Systems, Inc. Employee Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.64</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-08-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Amtech Systems, Inc. Employee Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>17.12</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-11-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Amtech Systems, Inc. Employee Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.01</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2023-12-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Amtech Systems, Inc. Employee Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.98</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2024-11-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Amtech Systems, Inc. Employee Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.87</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-10-04</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">One-half of the stock option granted vested on each of the first two anniversaries of the 08/06/2010 grant date.</footnote>
        <footnote id="F2">One-half of the stock option granted vested on each of the first two anniversaries of the 11/12/2010 grant date.</footnote>
        <footnote id="F3">One-half of the stock option granted vested on each of the first two anniversaries of the 12/12/2013 grant date.</footnote>
        <footnote id="F4">One-half of the stock option granted vested on each of the first two anniversaries of the 11/19/2014 grant date.</footnote>
        <footnote id="F5">One-half of the stock option granted vests on each of the first two anniversaries of the 10/04/2016 grant date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael Whang</signatureName>
        <signatureDate>2018-01-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
