-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 LEft7RqaDf5JEoagSwx89yk0kjxIcsGrwfVvs+jXrlpoV8lo1RZeZf+fySb3ZFVf
 JbZ7mZaE47EBJV6Ve7ppCw==

<SEC-DOCUMENT>0001209191-06-036710.txt : 20060615
<SEC-HEADER>0001209191-06-036710.hdr.sgml : 20060615
<ACCEPTANCE-DATETIME>20060615140548
ACCESSION NUMBER:		0001209191-06-036710
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060614
FILED AS OF DATE:		20060615
DATE AS OF CHANGE:		20060615

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WANSEM PAUL J VAN DER
		CENTRAL INDEX KEY:			0001223907

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-17297
		FILM NUMBER:		06906928

	MAIL ADDRESS:	
		STREET 1:		597 LOWELL ROAD
		CITY:			CONCORD
		STATE:			MA
		ZIP:			01742

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BTU INTERNATIONAL INC
		CENTRAL INDEX KEY:			0000840883
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				042781248
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		23 ESQUIRE ROAD
		CITY:			NORTH BILLERICA
		STATE:			MA
		ZIP:			01862
		BUSINESS PHONE:		5086674111

	MAIL ADDRESS:	
		STREET 1:		23 ESQUIRE ROAD
		CITY:			NORTH BILLERICA
		STATE:			MA
		ZIP:			01862

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BTU CORP
		DATE OF NAME CHANGE:	19881109
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-06-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000840883</issuerCik>
        <issuerName>BTU INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>BTUI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001223907</rptOwnerCik>
            <rptOwnerName>WANSEM PAUL J VAN DER</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>597 LOWELL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CONCORD</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01742</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Options (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.16</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-06-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>60000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.16</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-06-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>60000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">15,000 shares on June 14, 2007;
15,000 shares on June 14, 2008;
15,000 shares on June 14, 2009;
15,000 shares on June 14, 2010.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Paul J. van der Wansem</signatureName>
        <signatureDate>2006-06-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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