<Page>
EXHIBIT 4.1(n)
August 20, 2001
Atchison Casting Corporation
400 South 4th Street
Atchison, Kansas 66002-0188
Attention: Chief Financial Officer
Re: Atchison Casting Corporation (the "COMPANY") April 3, 1998 Amended
and Restated Credit Agreement by and among the Company,
Harris Trust and Savings Bank, as Agent and the Banks party
thereto (as heretofore amended, the "CREDIT AGREEMENT")
Ladies and Gentlemen:
Pursuant to the Tenth Amendment and Forbearance Agreement dated as of
April 13, 2001 (as modified by the July 30, 2001 letter, the "TENTH AMENDMENT")
the Bank Group agreed to temporarily forbear from enforcing its rights and
remedies with respect to the Credit Agreement through August 21, 2001 (the
"STANDSTILL EXPIRATION DATE"). The Company has requested that the Bank Group
extend the Standstill Expiration Date through September 12, 2001. Subject to the
terms and conditions hereof the Bank Group is willing to so extend the
Standstill Expiration Date.
Accordingly, effective upon the execution of this letter by the
Required Banks in the spaces provided for that purpose below (which execution
may be on separate counterparts of this letter, all of which are to constitute
one and the same instrument), (i) the Standstill Period shall be extended so
that the new Standstill Expiration Date shall be September 12, 2001, (ii) the
first sentence of paragraph 7 of the Tenth Amendment shall be amended by
deleting the percentage "43.6%" appearing therein and inserting in its place the
percentage "87.2%" and deleting the proviso thereto so that all proceeds from
the Penn Steel/PrimeCast Sale shall be applied as all other Liquidation Proceeds
and (iii) paragraph 8 of the Tenth Amendment shall be amended by deleting the
proviso "(but in any event excluding the first $750,000 of net proceeds of the
Penn Steel/PrimeCast Sale)" appearing therein. Except as specifically modified
hereby, all of the terms and conditions of the Credit Agreement shall remain in
full force and effect. Without limiting the generality of the foregoing, this
letter does not waive any of the other Defaults or Events of Default that now
exist.
<Page>
All defined terms used herein and not defined herein shall have the
same meaning herein as in the Tenth Amendment. This waiver shall be governed and
construed in accordance with the laws of the State of Illinois. All capitalized
terms used herein without definition shall have the same meaning herein as such
terms have in the Credit Agreement.
Very truly yours,
HARRIS TRUST AND SAVINGS BANK, in its individual
capacity as a Bank and as Agent
By: /s/ Neal Golub
Title: Vice President
COMMERCE BANK, N.A.
By:_____________________________________________
Title:__________________________________________
FIRSTAR BANK, N.A. (f/k/a Mercantile Bank)
By: /s/ Craig D. Buckely
Title: Vice President
KEY BANK NATIONAL ASSOCIATION
By: /s/ W. J.
Title: Vice President
COMERICA BANK
By: Andrew R. Craig
Title: Vice President
-2-
<Page>
HIBERNIA NATIONAL BANK
By:_____________________________________________
Title:__________________________________________
NATIONAL WESTMINSTER BANK PLC
Nassau Branch
By:_____________________________________________
Title:__________________________________________
New York Branch
By:_____________________________________________
Title:__________________________________________
WELLS FARGO BANK, NATIONAL ASSOCIATION
(successor by merger to Norwest
Bank Minnesota, N.A.)
By: /s/ Calvin R. Emmerson
Title: Vice President
Agreed and Accepted:
ATCHISON CASTING CORPORATION
By: /s/ Kevin T. McDermed
Title: Vice President
-3-