<PAGE>   1
                                                                     EXHIIT 4(f)

                                 AMENDMENT NO. 1
                                       TO
                           LOAN AND SECURITY AGREEMENT
                          DATED AS OF DECEMBER 1, 1998

                  THIS AMENDMENT NO. 1 dated as of December 23, 1998 (this
"Amendment") is entered into among BANKAMERICA BUSINESS CREDIT, INC., a Delaware
corporation ("BABC"), BNY FINANCIAL CORPORATION, a New York corporation ("BNY")
formerly known as Bank of New York Commercial Corporation, NATIONSBANK, N.A., a
national banking association ("NB") (BABC, BNY and NB and their respective
successors and assigns being sometimes hereinafter referred to collectively as
the "Lenders" and each of BABC, BNY and NB and its successors and assigns being
sometimes hereinafter referred to individually as a "Lender"), BANKAMERICA
BUSINESS CREDIT, INC., a Delaware corporation, as agent for the Lenders (in such
capacity as agent, the "Agent"), LACLEDE STEEL COMPANY, a Delaware corporation,
as debtor and debtor-in-possession (the "Parent"), with an office at One
Metropolitan Square, 211 North Broadway, St. Louis, Missouri 63102-2750, and
LACLEDE CHAIN MANUFACTURING COMPANY, a Delaware corporation, as debtor and
debtor-in-possession ("Laclede Chain"), with an office at One Metropolitan
Square, 211 North Broadway, St. Louis, Missouri 63102-2750, and LACLEDE MID
AMERICA INC., an Indiana corporation, as debtor and debtor-in-possession
("Laclede Mid America"), with an office at One Metropolitan Square, 211 North
Broadway, St. Louis, Missouri 63102-2750 (the Parent, Laclede Chain and Laclede
Mid America being sometimes hereinafter referred to collectively as the
"Borrowers" and each of the Parent, Laclede Chain and Laclede Mid America being
sometimes hereinafter referred to individually as a "Borrower").

                              W I T N E S S E T H:

                  WHEREAS, the Borrowers, the Lenders and the Agent are parties
to a certain Loan and Security Agreement dated as of December 1, 1998 (the "Loan
Agreement," capitalized terms used herein without definition having the meanings
given such terms in the Loan Agreement); and

                  WHEREAS, the Borrowers, the Lenders and the Agent have agreed
to amend the Loan Agreement on the terms and conditions hereinafter set forth;

                  NOW, THEREFORE, in consideration of the premises set forth
above, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Borrowers, the Lenders and the
Agent hereby agree as follows:

                  Section 1. Amendment of the Loan Agreement. Subject to the
fulfillment of the conditions precedent set forth in Section 2 below, the Loan
Agreement is amended as follows:


         (a) The reference in the definition of "Majority Lenders" to
"seventy-five percent (75.0%)" is hereby changed to "seventy-six percent
(76.0%)".

         (b) The following provision is added to the end of Section 7.2:
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         "Notwithstanding anything to the contrary contained herein, nothing in
         this Section 7.2 shall be construed as a representation that any of the
         Agent's liens or security interests have priority over the Carveout."

         (c) Section 8.25 is hereby deleted in its entirety and replaced with
         the following:

         "The Direct Contribution of the Alton Steel Operations will not be less
         than the following amounts for the following periods:

<TABLE>
<CAPTION>

                  Period                                 Amount
                  ------                                 ------

<S>                                                 <C>         
         Three months ending 3/31/99                 $(1,250,000)

         Six months ending 6/30/99                   $(1,500,000)

         Nine months ending 9/30/99                  $(1,500,000)

         Twelve months ending 12/31/99               $(1,700,000)
</TABLE>

         (d) The following provision is added to the end of Section 8.27:

         "Notwithstanding anything to the contrary herein, prior to an Event of
         Default, the Committee shall be entitled to use up to $100,000 of
         proceeds of Post-Petition Revolving Loans for the purpose of
         investigating the validity, extent, priority, and enforceability of the
         Pre-Petition Obligations and the Lenders' liens and security interests
         in the Pre-Petition Collateral."

         (e) The following provision is added to the beginning of Section
         8.29(h):

         "Except pursuant to order of the Bankruptcy Court after an actual
         hearing and sufficient notice thereof to the Agent and the Lenders with
         an opportunity to object,"

         (f) The proviso contained in Section 10.1(c)(iii) commencing with the
         words "provided, however" through the end of Section 10.1(c)(iii) is
         hereby deleted.

         (g) Section 10.1(f) is hereby deleted in its entirety and replaced with
         the following:

                  "(f) An order with respect to the Case shall be entered by the
         Bankruptcy Court, or any party shall file an application for an order
         with respect to the Case seeking relief, (i) appointing a trustee under
         Section 1104 of the Bankruptcy Code, (ii) appointing an examiner or
         responsible person with expanded powers similar to a trustee, or (iii)
         dismissing or converting the Case (or any part thereof) whether
         pursuant to Section 105, 305, or 1112 of the Bankruptcy 

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<PAGE>   3

         Code, or otherwise, and such application shall either have been granted
         in whole or in part or, within forty-five (45) after the filing
         thereof, shall not have been dismissed with prejudice."

         (h) Section 10.1(g) is hereby deleted in its entirety and replaced with
         the following:

             "(g) An order with respect to the Case shall be entered by the
         Bankruptcy Court confirming a plan of reorganization or liquidation in
         the Case other than a Consensual Plan, or any party shall file and seek
         to prosecute either (i) a plan of reorganization or liquidation in the
         Case, or (ii) a direct or indirect amendment of a plan of
         reorganization or liquidation in the Case, which plan, or direct or
         indirect amendment, does not have the prior written support of the
         Majority Lenders (which the Majority Lenders may withhold in their sole
         discretion), provided, however, that the foregoing shall not apply to
         non-material amendments to a plan which do not affect the Agent or the
         Lenders."

         (i) Sections 10.1(p) and (q) are hereby deleted in their entirety and
         replaced with the following:

             "(p) Any Termination Event occurs which the Agent believes
         could subject any Borrower or any ERISA Affiliate to an administrative
         claim in excess of $500,000;

             (q) The plan administrator of any Plan applies under Section
         412(d) of the Code for a waiver of the minimum funding standards of
         Section 412(a) of the Code and the Agent believes that the substantial
         business hardship upon which the application for such waiver is based
         could subject any Borrower or any ERISA Affiliate to an administrative
         claim in excess of $500,000;"

         (j) The following Section 10.1(u) is hereby added to the Loan
         Agreement:

         "All agreements incorporating the claims and liens of the Lenders from
         and after the effective date of a plan for the Debtors shall not have
         been filed in form and substance satisfactory to the Lenders with the
         Bankruptcy Court on or before fifteen (15) days prior to the voting
         deadline for such plan, or a party shall seek to amend or replace any
         such agreements after such filing without the written consent of the
         Majority Lenders (or, to the extent required herein, without the
         written consent of each Lender)."

         (k) The reference in Section 10.2(d) to "three (3) Business Days" is
         hereby changed to "five days".
                                   
         (l) The following provision is added to the end of Section 14.7:

             "If to the Committee:

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                  Mr. Larry Handlesman
                  Mr. Robert Raskin
                  Stroock, Stroock & Lavan
                  180 Maiden Lane
                  New York, NY 10038
                  Telecopy No. (212) 806-6006"


                  Section 2. Conditions to Amendment. This Amendment shall
become effective upon the receipt by the Agent by facsimile transmission of a
counterpart of this Amendment executed by each Borrower and each Lender, and
execution of this Amendment by the Agent (provided, that each Borrower and each
Lender shall promptly execute six applicable signature pages hereof and deliver
such pages to the Agent).

                  Section 3. Representations and Warranties. Each Borrower
hereby represents and warrants that (i) this Amendment constitutes a legal,
valid and binding obligation of such Borrower, enforceable against such Borrower
in accordance with its terms, (ii) the representations and warranties contained
in the Loan Agreement are correct in all material respects as though made on and
as of the date of this Amendment, and (iii) no Event of Default has occurred and
is continuing.

                  Section 4.  Reference to and Effect on the Loan Agreement.

                  (a) Upon the effectiveness of this Amendment, each reference
in the Loan Agreement to "this Agreement", "hereunder", "hereof", "herein", or
words of like import shall mean and be a reference to the Loan Agreement, as
amended hereby, and each reference to the Loan Agreement in any other document,
instrument or agreement executed and/or delivered in connection with the Loan
Agreement shall mean and be a reference to the Loan Agreement, as amended
hereby.

                  (b) Except as specifically amended above, the Loan Agreement
and all other documents, instruments and agreements executed and/or delivered in
connection therewith shall remain in full force and effect and are hereby
ratified and confirmed.

                  (c) The execution, delivery and effectiveness of this
Amendment shall not operate as a waiver of any right, power or remedy of the
Agent or the Lenders under the Loan Agreement, nor constitute a waiver of any
provision of the Loan Agreement, except as specifically set forth herein.

                  Section 5. Execution in Counterparts. This Amendment may be
executed in any number of counterparts and by different parties hereto in
separate counterparts, each of which when so executed and delivered shall be
deemed to be an original and all of which taken together shall constitute but
one and the same instrument.

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                  Section 6. Governing Law. This Amendment shall be governed by
and construed in accordance with the internal laws (as opposed to the conflicts
of laws provisions) of the State of Illinois.

                  Section 7. Section Titles. The section titles contained in
this Amendment are and shall be without substance, meaning or content of any
kind whatsoever and are not a part of the agreement between the parties hereto.

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                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be duly executed and delivered as of December 23, 1998.


                            LACLEDE STEEL COMPANY, as
                            Debtor and Debtor-in-Possession


                            By: /s/ M H Lane
                               -------------------------------------
                               Vice President


                            LACLEDE CHAIN MANUFACTURING COMPANY, as
                            Debtor and Debtor-in-Possession


                            By: /s/ M H Lane
                               -------------------------------------
                               Vice President


                            LACLEDE MID AMERICA INC., as
                            Debtor and Debtor-in-Possession


                            By: /s/ M H Lane
                               -------------------------------------
                               Vice President


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                             BANKAMERICA BUSINESS CREDIT, INC., as the Agent


                             By:  /s/ Michael Jasaitis   
                                -------------------------------------
                                Vice President


                             BANKAMERICA BUSINESS CREDIT, INC., as a Lender


                             By:  /s/ Michael Jasaitis  
                                -------------------------------------
                                Vice President

                                      S-2
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                             BNY FINANCIAL CORPORATION, as a Lender
                             and as successor to THE BANK OF NEW YORK
                             COMMERCIAL CORPORATION


                             By:  /s/ Anthony Viola 
                                ---------------------------------------
                                Vice President


                                      S-3
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                             NATIONSBANK, N.A., as a Lender


                             By: /s/ Scott Taylor
                                ---------------------------------
                                Vice President

                                      S-4