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                 THIRD AMENDMENT AND WAIVER TO CREDIT AGREEMENT

     THIS THIRD AMENDMENT AND WAIVER TO CREDIT AGREEMENT (this "Agreement"),
dated as of June 30, 1999, by and among IRON DYNAMICS, INC., an Indiana
corporation (the "Borrower") , the lenders listed on the signature pages hereof
and MELLON BANK, N.A., a national banking association, as agent for the Lenders
under the Credit agreement referred to below ( the "Agent").

                                    RECITALS:

     WHEREAS the Borrower, certain lenders, the Agent and Mellon Bank, N.A., as
Issuing Bank, entered into a Credit Agreement, dated as of December 31, 1997, as
amended by the Amendment and Waiver, dated as of June 10, 1998 and by the Second
Amendment to Credit Agreement, dated as of March 15, 1999 (as so amended, the
"Credit Agreement"), pursuant to which the Lenders have agreed to extend credit
to the Borrower;

     WHEREAS, the Borrower has requested the Lenders to effect certain
amendments and waivers to the Credit Agreement and the Required Lenders are
willing to do so to the extent provided herein;

     WHEREAS, capitalized terms not otherwise defined herein shall have the
meanings assigned thereto in the Credit Agreement.

     NOW, THEREFORE, the parties hereto, in consideration of their mutual
covenants and agreements hereinafter set forth and intending to be legally bound
hereby agree as follows:

     Section 1.              Amendments to Credit Agreement.

(a)  Section 6.03 (h) of the Credit Agreement is hereby amended by (i) changing
     the words "Unsecured Indebtedness of the Borrower to SDI in an aggregate
     principal amount not exceeding $10,000,000 at any time outstanding", which
     appears at the beginning thereof, to read "Unsecured Indebtedness of the
     Borrower to SDI in an aggregate principal amount not exceeding $25,000,000
     at any time outstanding" and (ii) adding at the end thereof the following:

               Such documentation, in the form of each of Exhibits FF and GG
               hereto, shall provide that the subordinated promissory note
               evidencing such Indebtedness and the rights of SDI thereunder
               shall not be sold or transferred by SDI without the prior written
               consent of the required Lenders except to (i) the Lenders and/or
               the Agent, as provided in the SDI Subordination Agreement and
               (ii) the lenders and/or the agents party to the Credit Agreement
               (Amended and Restated) dated as of June 30, 1994 and amended and
               restated as of June 30, 1997, entered into by SDI, the Lenders
               party thereto from time to time, Mellon Bank, N.A., as agent and
               as issuing bank, and certain co-agents named therein.

(b)  Exhibit FF (Subordinated Promissory Note) to the Credit Agreement is hereby
     amended by substituting therefore Exhibit FF (consisting of a form of
     subordinated promissory note and a form of letter agreement from SDI with
     respect thereto) attached hereto.

(c)  For the purpose of extending the deadline for achieving the Preliminary
     Acceptance Date, the date "June 30, 1999" appearing in each of the
     following Sections of the Credit Agreement is hereby changed to "March 31,
     2000":

     Section 3.26, titled "Project Compliance With Laws; Permits"

     Section 5.01 (j) (viii), titled "Notice of Certain Events"

     Section 5.14, titled "Construction of the Project"

     Section 6.19, titled "Change Orders"

     Section 7.01 (q) and 7.01 (v), titled "Events of Default"


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(d)  For the purpose of extending the deadline for achieving the Final
     Acceptance Date, the date "March 31, 2000" appearing in each of the
     following Sections of the Credit Agreement is hereby changed to "December
     31, 2000"

     Section 5.01 (j) (viii), titled "Notice of Certain Events"

     Section 5.14, titled "Construction of the Project"

     Section 6.19, titled "Change Orders"

     Section 7.01 (q) and 7.01 (v), titled "Events of Default"

(e)  The date "December 31, 2000" appearing in Section 5.14 of the Credit
     Agreement is hereby changed to "September 30, 2001".

(f)  Section 6.01 (c) of the Credit Agreement is hereby amended to read in its
     entirety as follows:

               (c) Negative EBITDA. During the period from January 1, 1998
               through December 31, 2000 cumulative negative EBITDA of the
               Borrower at the end of any fiscal quarter shall not exceed the
               sum of (i) $7,000,000 and (ii) an amount, not to exceed
               $8,000,000, which is equal to the amount by which the aggregate
               principal amount of unsecured Indebtedness of the Borrower to SDI
               outstanding at the end of such quarter (or, in the case of the
               quarter ending June 30, 1999, outstanding on July 31, 1999) as a
               result of advances by SDI in accordance with Section 6.03 (h)
               hereof exceeds $10,000,000; provided, that if, on any date in any
               fiscal quarter commencing with the fiscal quarter in which the
               Preliminary Acceptance Date occurs, the amount of unsecured
               Indebtedness to SDI outstanding in accordance with Section 6.03
               (h) hereof is less than $25,000,000, the maximum amount of
               cumulative negative EBITDA (the EBITDA Cap") permitted by the
               preceding terms of this Section 6.01 (c) at the end of such
               quarter will be reduced by an amount equal to (A) the difference
               between $25,000,000 and the principal amount of such unsecured
               Indebtedness to SDI outstanding at the end of such quarter minus
               amounts by which the EBITDA Cap previously has been so reduced
               under this proviso divided by (B) four minus the number of fiscal
               quarters in which the EBITDA Cap previously has been so reduced.
               In the event that the amount of such unsecured Indebtedness to
               SDI increases subsequent to one or more such reductions to the
               EBITDA Cap, the amount of such increase shall be restored to the
               EBITDA Cap on a one-for-one basis up to the amount of such
               previous reductions. In no event shall the EBITSA Cap be reduced
               below $7,000,000.

(g)  Section 6.01 (d) if the Credit Agreement is hereby amended to read in its
     entirety as follows:

               (d) Funded Indebtedness to EBITDA. The ratio of (x) Funded
               Indebtedness minus the amount of funded Indebtedness of the
               Borrower to SDI outstanding in accordance with Section 6.03 (h)
               hereof, minus the amount on deposit in the Debt Service Reserve
               Account to (y) EBITDA for each Measurement Period ending in the
               calendar years 1999 or 2000 shall be not greater than 4.0 to 0 on
               the last day of each such Measurement Period and for each
               Measurement Period ending after the calendar year 2000, shall be
               not greater than 4.0 to 1 on the last day of each such
               Measurement Period.

(h)  The definition of "EBITDA" appearing in Section 1.01 of the Credit
     Agreement is hereby amended by adding thereto, prior to the words "all as
     determined in accordance with GAAP", the following:

               Plus (j) the amount of insurance deductibles paid, to the extent
               included in determining such Net Income, and minus (k) insurance
               proceeds received to the extent included (and not offset by a
               corresponding loss) in determining such Net Income,

(i)  Section 1.01 of the Credit Agreement is hereby amended by amending the
     definitions of "Financial Covenant Date" and "Measurement Period" appearing
     therein to read, in each case in its entirety, as follows:

               "Financial Covenant Date" shall mean the earlier of (a) the last
               day of the first fiscal quarter after the Final Acceptance Date
               and (b) March 31, 2001.

               "Measurement Period" (i) for purposes of Section 6.01 shall have
               meaning set forth in Section 6.01 (b) and (ii) for all other
               purposes shall mean a period of four consecutive calendar
               quarters.

(j)  Section 9.14 of the Credit Agreement is hereby amended by adding thereto a
     new Subsection 9.14 (f) to read in its entirety as follows:


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               (f)  Notwithstanding anything to the contrary contained herein,
                    any Lender (a "Granting Lender") may grant to a special
                    purpose funding vehicle (an "SPC") the option to fund all or
                    part of any Loan that such Granting Lender would otherwise
                    be obligated to fund pursuant to this Agreement: provided
                    that (i) nothing herein shall constitute a commitment by any
                    SPC to fund any Loan, and (ii) if an SPC elects not to
                    exercise such option or otherwise fails to fund any part of
                    such Loan, the Granting Lender shall be obligated to fund
                    such Loan pursuant to the terms hereof. The funding of a
                    Loan by an SPC hereunder shall utilize the Commitment of the
                    Granting Lender to the same extent, and as if, such Loan
                    were funded by the Granting Lender. Each party hereto hereby
                    agrees that no SPC shall be liable for any indemnity or
                    payment under this agreement for which a Lender would
                    otherwise be liable for so long as, and to the extent, the
                    Granting Lender provides such indemnity or makes such
                    payment. This Section 9.14 (f) may not be amended without
                    the prior written consent of each Granting Lender, all or
                    any part of whose Loans is being funded by an SPC at the
                    time of such amendment.

(k)  Article III of the Credit Agreement is hereby amended by adding thereto a
     new Section 3.33 to read in its entirety as follows, and by its execution
     hereof the Borrower hereby represents and warrants as follows:

              3.33. Year 2000. The Borrower has reviewed the areas within its
                    business and operations which could be adversely affected
                    by, and has developed or is developing a program to address
                    on a timely basis, the "Year 2000 Problem" (that is, the
                    risk that computer applications used by the Borrower may be
                    unable to recognize and perform properly date-sensitive
                    functions involving certain dates prior to and any date on
                    or after December 31, 1999), and have made related
                    appropriate inquiry of material suppliers and vendors. Based
                    on such review, program and inquiry, the Borrower believes
                    that the "Year 2000 Problem" will not have a Material
                    Adverse Effect on the Borrower. From time to time, at the
                    request of the Agent the Borrower shall provide to the Agent
                    such updated information or documentation as is requested
                    regarding the status of Borrower's efforts to address the
                    "Year 2000 Problem".

     Section 2. Consent to Amendment of Subordinated Promissory Note. The Agent
     and the Required Lenders hereby consent to the amendment, in the manner
     described in Sections 1 (a) and 1 (b) if this Agreement, of the
     Subordinated Promissory Note (the "Subordinated Promissory Note") dated as
     of March 15, 1999 from the Borrower to SDI and the attachment thereof to
     the Subordination Agreement (the "SDI Subordination Agreement"), dated as
     of March 15, 1999, made by the Borrower and SDI in favor of the Lenders and
     the Agent.

     Section 3. Waiver With Respect to Mechanics Lien. The Required Lenders
     hereby waive any Event of Default and any Potential Default which may have
     arisen pursuant to Section 7.01 (j) of the Credit Agreement as a result of
     the recording on November 19, 1998 in the office of the Recorder DeKalb
     County, Indiana, of a Notice of Intention to Hold Mechanics Lien by Taft
     Contracting Company, Inc. (such lien, the "Taft Mechanics Lien"), provided,
     that, as of and after July 15, 1999, such waiver shall terminate and have
     no further effect if on such date the Agent shall not have received a copy
     of a surety bond providing for the payment of all obligations (up to
     $1,500,000) relating to such Taft Mechanics Lien and a stipulation and
     order providing for release of the real estate and improvements of the
     Borrower and SDI from the Taft Mechanics Lien, together with evidence that
     each thereof has been duly recorded, and in each case in form and substance
     satisfactory to the Agent.

     Section 4. Directions to Agent. The Required Lenders hereby direct the
     Agent to execute and deliver the Agreement.

     Section 5. Miscellaneous. (a) This Agreement shall become effective, as of
     its date, upon (i) the execution and delivery hereof by the Required
     Lenders, the Borrower and the Agent and (ii) the delivery to the Agent of a
     fully executed copy of the SDI Subordination Agreement in the form of
     Exhibit GG to the Credit Agreement, to which there has been attached a copy
     of the Subordinated Promissory Note delivered by IDI to SDI in the form of
     part of Exhibit FF attached to the Agreement, and of the letter agreement
     which is part of Exhibit FF Attached to the Agreement.

     (b)  The Credit Agreement, as amended or modified by this Agreement, is in
          all respects ratified, approved and confirmed and shall, as so amended
          and modified, remain in full force and effect. From and after the date
          hereof, all references to the "Agreement" in the Credit Agreement and
          in the other Loan Documents shall be deemed to be references to the
          Credit Agreement as amended and modified by this Agreement.

     (c)  This Agreement shall be deemed to be a contract under the laws of the
          State of New York and for all purposes shall be governed by and
          construed and enforced in accordance with the laws of said State.

     (d)  This Agreement may be executed in any number of counterparts and by
          different parties hereto on separate counterparts, each of which, when
          so executed, shall be deemed an original, but all such counter parts
          shall constitute but one and the same instrument.


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IN WITNESS WHEREOF, the parties hereto, by their officers thereunto duly
authorized, have executed and delivered this agreement as of the date first
above written.

                                           IRON DYNAMICS, INC.

                                           By:         s/s  Larry Lehtinen
                                              -------------------------------
                                           Title: Vice President

                                           Mellon Bank
                                           By:         s/s Jack Walsh
                                              -------------------------------
                                           Title:  Vice President

                                           Kreditanstalt fur Wiederaufbau
                                           By:         s/s Illegible
                                              -------------------------------
                                           Title:    First Vice President &
                                                       Senior Project Manager

                                           National City Bank, Indiana
                                           By:         s/s Gerald Witte
                                              -------------------------------
                                           Title:   Senior Vice President

                                           LaSalle Bank National Association
                                           By:         s/s Illegible
                                              -------------------------------
                                           Title:   Assistant Vice President




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IN WITNESS WHEREOF, the parties hereto, by their officers thereunto duly
authorized, have executed and delivered this agreement as of the date first
above written.

                                           IRON DYNAMICS, INC.

                                           By:         s/s  Larry Lehtinen
                                              -------------------------------
                                           Title: Vice President

                                           Mellon Bank
                                           By:         s/s Jack Walsh
                                              -------------------------------
                                           Title:  Vice President

                                           Kreditanstalt fur Wiederaufbau
                                           By:         s/s Illegible
                                              -------------------------------
                                           Title:    First Vice President &
                                                       Senior Project Manager

                                           National City Bank, Indiana
                                           By:         s/s Gerald Witte
                                              -------------------------------
                                           Title:   Senior Vice President

                                           National City Bank, Indiana
                                           f/k/a Fort Wayne National Bank
                                           By:         s/s Gerald Witte
                                              -------------------------------
                                           Title:   Senior Vice President

                                           LaSalle Bank National Association
                                           By:         s/s Illegible
                                              -------------------------------
                                           Title:   Assistant Vice President




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