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                                   EXHIBIT 4.1


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            SIXTH AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

         This Sixth Amendment to Amended and Restated Credit Agreement (the
"AMENDMENT") dated as of February 15, 2000 among Atchison Casting Corporation
(the "BORROWER"), the Banks, and Harris Trust and Savings Bank, as Agent;

                              W I T N E S S E T H:

         WHEREAS, the Borrower, Guarantors, Banks and Harris Trust and Savings
Bank, as Agent, have heretofore executed and delivered an Amended and Restated
Credit Agreement dated as of April 3, 1998 (as amended through the Fifth
Amendment thereto dated as of December 21, 1999, the "CREDIT AGREEMENT"); and

         WHEREAS, the parties hereto desire to amend the Credit Agreement as
provided herein;

         NOW, THEREFORE, for good and valuable consideration the receipt and
sufficiency of which is hereby acknowledged, the parties hereto agree that the
Credit Agreement shall be and hereby is amended as follows:

         1.       Section 3 of the Credit Agreement is hereby amended by
inserting new Sections 3.2 and 3.3 immediately following Section 3.1 as follows:

                           SECTION 3.2. COLLATERAL. The Obligations shall be
                  secured by valid, perfected and enforceable Liens on all
                  right, title and interest of the Borrower and each Guarantor
                  in all property described in the Collateral Documents.

                           SECTION 3.3. FURTHER ASSURANCES. The Borrower agrees
                  that it shall, and shall cause each Subsidiary to, from time
                  to time at the request of the Agent or the Required Banks,
                  execute and deliver such documents and do such acts and things
                  as the Agent or the Required Banks may reasonably request in
                  order to provide for or perfect or protect such Liens on the
                  Collateral. In the event the Borrower or any Subsidiary forms
                  or acquires any other Subsidiary after the date hereof, the
                  Borrower shall within 10 Business Days of such formation or
                  acquisition cause such newly formed or acquired Subsidiary, to
                  execute a Guaranty and any such Subsidiary to execute such
                  Collateral Documents as the Agent may then reasonably require,
                  and the Borrower shall also deliver to the Agent, or cause
                  such Subsidiary to deliver to the Agent, at the Borrower's
                  cost and expense, such other instruments, documents,
                  certificates and opinions reasonably required by the Agent in
                  connection therewith.


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         2.       Section 4 of the Credit Agreement is hereby amended by adding
thereto the following definitions in the appropriate alphabetical locations:

                   "CANADIAN SECURITY AGREEMENTS" means those certain Security
                  Agreements and Hypothecs each dated as of February 15, 2000
                  from each of the Foreign Guarantors to the Collateral Agent,
                  as the same may be amended, modified or supplemented from time
                  to time.

                   "COLLATERAL" means all properties, rights, interests and
                  privileges from time to time subject to the Liens granted to
                  the Collateral Agent, or any security trustee therefor, by the
                  Collateral Documents.

                  "COLLATERAL AGENT" means Harris Trust and Savings Bank in its
                  capacity as Collateral Agent under the Intercreditor Agreement
                  and any successor to it in such capacity.

                  "COLLATERAL DOCUMENTS" means the Guaranty Agreement, the
                  Security Agreement, the Canadian Security Agreements, the
                  Pledge Agreement and all other security agreements, pledge
                  agreements, assignments, financing statements and other
                  documents as shall from time to time secure or relate to the
                  Obligations or any part thereof.

                  "DOMESTIC GUARANTORS" means and includes each Guarantor
                  organized under the laws of a jurisdiction within the United
                  States of America.

                  "FOREIGN GUARANTORS" means and includes each Guarantor
                  organized under the laws of a jurisdiction outside the United
                  States of America.

                   "SECURITY AGREEMENT" means that certain Security Agreement
                  dated the date of this Agreement among the Borrower, the
                  Domestic Guarantors and the Collateral Agent, as the same may
                  be amended, modified, supplemented or restated from time to
                  time.

         3.       The following definitions appearing in Section 4 of the Credit
Agreement shall each be amended in their entirety and as so amended shall be
restated to read as follows:

                  "CREDIT DOCUMENTS" means this Agreement, the Notes, the
                  Collateral Documents, the Applications and the Letters of
                  Credit.

                  "INTERCREDITOR AGREEMENT" means the Intercreditor and
                  Collateral Agency Agreement dated as of February 15, 2000 by
                  and among the


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                  Collateral Agent, the Banks and Teachers Insurance and
                  Annuity Association of America.

         4.       Section 7.5 of the Credit Agreement shall be amended by adding
thereto a new sentence immediately at the end thereof which reads as follows:

                  "The Borrower shall in any event maintain, and cause each
                  Subsidiary to maintain, insurance on the Collateral to the
                  extent required by the Collateral Documents.

         5.       Section 7.9 of the Credit Agreement shall be amended by (i)
striking the period appearing at the end of Subsection (h) thereof and
substituting therefor a semi-colon followed by the word "and", and (ii) adding
thereto a new Subsection (i) which reads as follows:

                           (i)      the Liens granted in favor of the Collateral
                  Agent pursuant to the Collateral Documents.

         6.       Section 8.1(b) of the Credit Agreement shall be amended in its
entirety and as so amended shall be restated to read as follows:

                           (b)      default by the Borrower in the observance or
                  performance of any covenant set forth in Section 7.1, 7.6(h),
                  7.9 through 7.20 or 7.22 hereof or of any provision in any
                  Credit Document dealing with the remittance to the Collateral
                  Agent of the proceeds of Collateral or requiring the
                  maintenance of insurance thereon;

         7.       Section 11.13(ii) of the Credit Agreement is hereby amended in
its entirety and as so amended shall be restated to read as follows:

                           (ii)     No amendment or waiver pursuant to this
                  Section shall, unless signed by each Bank, change the
                  provisions of this Section, the definition of "REQUIRED
                  BANKS", or any condition precedent set forth in Section 6
                  hereof or the provisions of Sections 8.1(f), 8.1(g) or 8.3, or
                  9, or release any Subsidiary from its obligations under a
                  Guaranty Agreement, or release all or substantially all of the
                  Collateral (except as otherwise provided for in the Credit
                  Documents), or affect the number of Banks required to take any
                  action hereunder.

         8.       The Borrower represents and warrants to each Bank and the
Agent that (a) each of the representations and warranties set forth in Section 5
of the Credit Agreement (as updated pursuant to this Amendment) is true and
correct on and as of the date of this Amendment as if made on and as of the date
hereof and as if each reference therein to the Credit Agreement referred to the
Credit Agreement as amended hereby; (b) after giving effect to this Amendment,
no Default and no Event of Default has occurred and is continuing; and (c)
without limiting the effect of the foregoing, the Borrower's execution, delivery
and performance of this Amendment


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have been duly authorized, and this Amendment has been executed and delivered
by duly authorized officers of the Borrower.

         9.       This Amendment shall become effective upon the satisfaction of
each of the following conditions precedent:

                           (a)      the Borrower, the Required Banks, and the
                  Agent shall have executed and delivered this Amendment and the
                  Guarantors shall have executed the consent attached hereto.

                           (b)      the Agent shall have received the Security
                  Agreement and Canadian Security Agreement duly executed by the
                  Borrower and its Subsidiaries, UCC financing statements to be
                  filed against the Borrower and each Subsidiary, as debtor, in
                  favor of the Collateral Agent, as secured party; and

                           (c)      The Agent shall have received for the
                  account of the Banks such other agreements, instruments,
                  documents, certificates, and opinions as the Agent may
                  reasonably request.

         10.      The Borrower agrees to deliver to the Agent no later than 7
days after the date hereof the favorable written opinion of counsel to the
Borrower, in form and substance satisfactory to the Agent. Failure to deliver
such opinion by such date shall constitute an Event of Default under the Credit
Agreement.

         This Amendment may be executed in any number of counterparts and by
different parties hereto on separate counterpart signature pages, each of which
when so executed shall be an original but all of which shall constitute one and
the same instrument. Except as specifically amended and modified hereby, all of
the terms and conditions of the Credit Agreement and the other Credit Documents
shall remain unchanged and in full force and effect. All references to the
Credit Agreement in any document shall be deemed to be references to the Credit
Agreement as amended hereby. All capitalized terms used herein without
definition shall have the same meaning herein as they have in the Credit
Agreement. This Amendment shall be construed and governed by and in accordance
with the internal laws of the State of Illinois.


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         Dated as of the date first above written.

                           ATCHISON CASTING CORPORATION

                           By: /s/ Kevin T. McDermed
                               ------------------------------------------------
                           Title: V.P. & Treasurer
                                  ---------------------------------------------

                           HARRIS TRUST AND SAVINGS BANK, in its individual
                              capacity as a Bank and as Agent

                           By: /s/ Len E. Meyer
                               ------------------------------------------------
                           Title: Vice President
                                  ---------------------------------------------

                           COMMERCE BANK, N.A.

                           By: /s/ Dennis R. Block
                               ------------------------------------------------
                           Title: Senior Vice President
                                  ---------------------------------------------

                           MERCANTILE BANK

                           By: /s/ Barry P. Sullivan
                               ------------------------------------------------
                           Title: Vice President
                                  ---------------------------------------------

                           KEY BANK NATIONAL ASSOCIATION

                           By: /s/ Daniel M. Lally
                               ------------------------------------------------
                           Title: Assistant Vice President
                                  ---------------------------------------------


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                           COMERICA BANK

                           By: /s/ Jeffrey E. Peck
                               ------------------------------------------------
                           Title: Vice President
                                  ---------------------------------------------

                           HIBERNIA NATIONAL BANK

                           By: /s/ Troy J. Villafarro
                               ------------------------------------------------
                           Title: Senior Vice President
                                  ---------------------------------------------

                           NATIONAL WESTMINSTER BANK PLC

                           Nassau Branch

                           By: /s/ P. Mills
                               ------------------------------------------------
                           Title: Senior Corporate Manager
                                  ---------------------------------------------

                           New York Branch

                           By: /s/ P. Mills
                               ------------------------------------------------
                           Title: Senior Corporate Manager
                                  ---------------------------------------------

                           WELLS FARGO BANK, NATIONAL ASSOCIATION
                              (successor by merger to Norwest Bank
                              Minnesota, N.A.)

                           By: /s/ R. Duncan Sinclair
                               ------------------------------------------------
                           Title: Vice President
                                  ---------------------------------------------