EXHIBIT 4.4C


                          THIRD SUPPLEMENTAL INDENTURE

      THIS THIRD SUPPLEMENTAL INDENTURE is dated as of December 31, 2002, among
STEEL DYNAMICS, INC., an Indiana corporation (the "Company"), SDI INVESTMENT
COMPANY, a Delaware corporation, (the "Initial Subsidiary Guarantor"), DYNAMIC
BAR PRODUCTS, LLC, an Indiana limited liability company (the "Second Subsidiary
Guarantor"), STLD HOLDINGS, INC. an Indiana corporation, FERROUS RESOURCES, LLC,
an Indiana limited liability company (STLD Holdings, Inc. and Ferrous Resources,
LLC may individually be referred to as the "Additional Subsidiary Guarantor" and
collectively as the "Additional Subsidiary Guarantors"), STEEL DYNAMICS SALES
NORTH AMERICA, INC., an Indiana corporation (the "New Subsidiary Guarantor"),
and FIFTH THIRD BANK, INDIANA, a state banking association, as trustee (the
"Trustee").

                                    RECITALS:

      The Company, the Initial Subsidiary Guarantor and the Trustee have duly
authorized, executed and delivered an Indenture dated as of March 26, 2002 (the
"Original Indenture") in connection with the issuance initially of up to
$200,000,000 aggregate principal amount of the Company's 9-1/2% Senior Notes due
2009 (the "Notes") as provided in the Original Indenture.

      The Company, the Initial Subsidiary Guarantor, the Second Subsidiary
Guarantor, and the Trustee entered into a First Supplemental Indenture dated as
of September 6, 2002.

      The Company, the Initial Subsidiary Guarantor, the Second Subsidiary
Guarantor, the Additional Subsidiary Guarantors and the Trustee entered into a
Second Supplemental Indenture dated as of September 30, 2002.

      This Third Supplemental Indenture is being executed and delivered by the
Company, the Initial Subsidiary Guarantor, the Second Subsidiary Guarantor, the
Additional Subsidiary Guarantors and the New Subsidiary Guarantor pursuant to
the provisions of Section 4.20 and Section 9.01(2) of the Original Indenture.

      This Third Supplemental Indenture (together with the Original Indenture,
the First Supplemental Indenture and the Second Supplemental Indenture,
collectively the "Indenture") is subject to, and shall be governed by, the
provisions of the Trust Indenture Act of 1939, as amended, that are required to
be a part of and to govern indentures qualified under the Trust Indenture Act of
1939, as amended.

            AND THIS THIRD SUPPLEMENTAL INDENTURE FURTHER WITNESSETH:

      For and in consideration of the premises, it is mutually covenanted and
agreed, for the equal and proportionate benefit of all Holders, as follows:

                                  ARTICLE ONE

                               Guaranty of Notes

      Section 1.01. Note Guarantee; Limitation of Liability. (a) Subject to the
provisions of Article Ten of the Original Indenture, the New Subsidiary
Guarantor hereby, jointly and severally with the Initial Subsidiary Guarantor,
the Second Subsidiary Guarantor and the Additional Subsidiary Guarantors, fully
and unconditionally guarantee to each Holder of Notes and to the Trustee on
behalf of the Holders: (i) the due and punctual payment of the principal of,
premium, if any, on and interest on each Note, when and as the same shall become
due and payable, whether at maturity, by acceleration or otherwise, the due and
punctual payment of interest on the overdue principal of and interest, if any,
on the Notes, to the extent lawful, and the due and punctual performance of all
other obligations of the Company to the Holders or the Trustee, all in
accordance with the terms of such Note, the Original Indenture, the First
Supplemental Indenture, the Second Supplemental Indenture and this Third
Supplemental Indenture and (ii) in the case of any extension of time of payment
or renewal of any Notes or any of such other obligations, that the same will be
promptly paid in full when due or performed in accordance with the terms of the
extension or renewal, at Stated Maturity, by acceleration or otherwise, subject,
however, in the case of clauses (i) and (ii) above, to the limitations set forth
in the second paragraph of Section 10.01 of the Original Indenture.

      (b)   The undersigned, and by their acceptance of this Third Supplemental
Indenture, hereby confirm that it is the intention of all such Persons that this
Third Supplemental Indenture, the Original Indenture, the First Supplemental
Indenture and the Second Supplemental Indenture and the obligations of the
undersigned hereunder and thereunder not constitute a fraudulent transfer or
conveyance for purposes of Bankruptcy Law, the Uniform Fraudulent Conveyance
Act, the Uniform Fraudulent Transfer Act or any similar foreign, federal or
state law to the extent applicable to this Third Supplemental Indenture, the
Original Indenture, the First Supplemental Indenture, the Second Supplemental
Indenture and the obligations of the undersigned hereunder and thereunder. To
effectuate the foregoing intention, the undersigned hereby irrevocably agree
that the obligations of the undersigned under this Third Supplemental Indenture,
the Original Indenture, the First Supplemental Indenture and the Second
Supplemental Indenture at any time shall be limited to the maximum amount as
will result in the obligations of the undersigned under this Third Supplemental
Indenture, the Original Indenture, the First Supplemental Indenture and the
Second Supplemental Indenture not constituting a fraudulent transfer or
conveyance.

      Section 1.02. Obligations under the Original Indenture. The New Subsidiary
Guarantor hereby agrees, as of the date first above written, to be bound as a
Subsidiary Guarantor by all of the terms and conditions of the Original
Indenture to the same extent as each of the other Subsidiary Guarantors
thereunder. The New Subsidiary Guarantor further agrees, as of the date first
above written, that each reference in the Original Indenture to a "SUBSIDIARY
GUARANTOR" shall also mean and be a reference to the New Subsidiary Guarantor,
and each reference in any of the Notes to a "SUBSIDIARY GUARANTOR" shall also
mean and be a reference to the New Subsidiary Guarantor.


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      Section 1.03. Covenants and Agreements. The New Subsidiary Guarantor makes
each covenant and agreement set forth in Article Ten of the Original Indenture
to the same extent as each other Subsidiary Guarantor.

                                  ARTICLE TWO

                                 Miscellaneous

      Section 2.01. Remainder of Original Indenture Unaffected. Except as
specifically provided in Article One above, the terms of the Original Indenture
shall remain unchanged and in full force and effect, and shall govern the
interpretation and application of this Third Supplemental Indenture.

      Section 2.02. Duplicate Originals; Delivery by Telecopier. The parties may
sign any number of copies of this Third Supplemental Indenture. Each signed copy
shall be an original, but all of them together represent the same agreement.
Delivery of an executed counterpart of a signature page to this Third
Supplemental Indenture by telecopier shall be effective as delivery of an
original executed counterpart of this Third Supplemental Indenture.

      Section 2.03. Separability. In case any provision in this Third
Supplemental Indenture shall be invalid, illegal or unenforceable, the validity,
legality and enforceability of the remaining provisions shall not in any way be
affected or impaired thereby.



                              [End of Article Two]


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                                   SIGNATURES

      IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed, all as of the date first written above.

"Company"                               STEEL DYNAMICS, INC.

                                        By:  ___________________________________
                                        Its  ___________________________________


"Initial Subsidiary Guarantor"          SDI INVESTMENT COMPANY

                                        By:  ___________________________________
                                        Its  ___________________________________



"Second Subsidiary Guarantor"           DYNAMIC BAR PRODUCTS, LLC

                                        By:  ___________________________________
                                        Its  ___________________________________



"Additional Subsidiary Guarantor"       STLD HOLDINGS, INC.

                                        By:  ___________________________________
                                        Its  ___________________________________



"Additional Subsidiary Guarantor"       FERROUS RESOURCES, LLC

                                        By:  ___________________________________
                                        Its  ___________________________________



"Trustee"                               FIFTH THIRD BANK, INDIANA

                                        By:  ___________________________________
                                        Its  ___________________________________


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"New Subsidiary Guarantor"              STEEL DYNAMICS SALES NORTH AMERICA, INC.

                                        By:  ___________________________________
                                        Its  ___________________________________


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