EXHIBIT 31.1


                      Chief Executive Officer Certification
                     Required by Item 307 of Regulation S-K
            As Promulgated by the Securities and Exchange Commission
            Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002


I, Keith E. Busse, Chairman, President and Chief Executive Officer, certify
that:

         1. I have reviewed this annual report on Form 10-K of Steel Dynamics,
Inc.;

         2. Based on my knowledge, this annual report does not contain any
untrue statement of a material fact or omit to state a material fact necessary
to make the statements made, in light of the circumstances under which such
statements were made, not misleading with respect to the period covered by this
annual report;

         3. Based on my knowledge, the financial statements, and other financial
information included in this annual report, fairly present in all material
respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this annual report;

         4. The registrant's other certifying officers and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-14 and 15d-14 for the registrant and have:

                  (a) Designed such disclosure controls and procedures to ensure
         that material information relating to the registrant, including its
         consolidated subsidiaries, is made known to us by others within those
         entities, particularly during the period in which this annual report is
         being prepared;

                  (b) Evaluated the effectiveness of the registrant's disclosure
         controls and procedures as of a date within 90 days prior to the filing
         date of this annual report (the "Evaluation Date"); and

                  (c) Presented in this annual report our conclusions about the
         effectiveness of the disclosure controls and procedures based on our
         evaluation as of the Evaluation Date;

         5. The registrant's other certifying officers and I have disclosed,
based on our most recent evaluation, to the registrant's auditors and the audit
committee of registrant's board of directors:

                  (a) All significant deficiencies in the design or operation of
         internal controls which could adversely affect the registrant's ability
         to record, process, summarize and report financial data and have
         identified for the registrant's auditors any material weaknesses in
         internal controls; and

                  (b) Any fraud, whether or not material, that involves
         management or other employees who have a significant role in the
         registrant's internal controls; and



                                 /S/ KEITH E. BUSSE
                                 ----------------------------------------------
                                 Keith E. Busse
                                 Chairman, President and Chief Executive Officer
                                 March 12, 2004