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        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0002019064</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001022671</issuerCik>
            <issuerName>STEEL DYNAMICS INC.</issuerName>
            <secFileNumber>000-21719</secFileNumber>
            <issuerAddress>
                <ns2:street1>7575 West Jefferson Blvd.</ns2:street1>
                <ns2:city>Fort Wayne</ns2:city>
                <ns2:stateOrCountry>IN</ns2:stateOrCountry>
                <ns2:zipCode>46804</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(260) 969-3500</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>CHAD BICKFORD</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>2000</noOfUnitsSold>
            <aggregateMarketValue>269725.40</aggregateMarketValue>
            <noOfUnitsOutstanding>154302528</noOfUnitsOutstanding>
            <approxSaleDate>10/28/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/07/2010</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>174</amountOfSecuritiesAcquired>
            <paymentDate>12/07/2010</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/03/2012</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>170</amountOfSecuritiesAcquired>
            <paymentDate>12/03/2012</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/02/2013</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>146</amountOfSecuritiesAcquired>
            <paymentDate>12/02/2013</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/21/2014</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1059</amountOfSecuritiesAcquired>
            <paymentDate>11/21/2014</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/04/2009</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>190</amountOfSecuritiesAcquired>
            <paymentDate>12/04/2009</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/01/2011</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>145</amountOfSecuritiesAcquired>
            <paymentDate>12/01/2011</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/03/2014</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>116</amountOfSecuritiesAcquired>
            <paymentDate>11/03/2014</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>10/28/2024</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Chad Bickford</signature>
        </noticeSignature>
    </formData>
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144
0002019064
XXXXXXXX
LIVE
0001022671
STEEL DYNAMICS INC.
000-21719
7575 West Jefferson Blvd.
Fort Wayne
IN
46804
(260) 969-3500
CHAD BICKFORD
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
2000
269725.40
154302528
10/28/2024
NASDAQ
Common
12/07/2010
Restricted stock vesting under a registered plan
Issuer
N
174
12/07/2010
Services Rendered
Common
12/03/2012
Restricted stock vesting under a registered plan
Issuer
N
170
12/03/2012
Services Rendered
Common
12/02/2013
Restricted stock vesting under a registered plan
Issuer
N
146
12/02/2013
Services Rendered
Common
11/21/2014
Restricted stock vesting under a registered plan
Issuer
N
1059
11/21/2014
Services Rendered
Common
12/04/2009
Restricted stock vesting under a registered plan
Issuer
N
190
12/04/2009
Services Rendered
Common
12/01/2011
Restricted stock vesting under a registered plan
Issuer
N
145
12/01/2011
Services Rendered
Common
11/03/2014
Restricted stock vesting under a registered plan
Issuer
N
116
11/03/2014
Services Rendered
Y
10/28/2024
/s/ Chad Bickford