<PAGE>   1
                                                                    EXHIBIT 10.2


                           NICHOLS 401(k) SAVINGS PLAN

                        AGREEMENT FOR ADOPTION AND MERGER
         OF THE TEMROC METALS, INC. NON-BARGAINING UNIT EMPLOYEES 401(k)
                    PLAN INTO THE NICHOLS 401(k) SAVINGS PLAN

                  THIS AGREEMENT by and between Quanex Corporation, a
corporation ("Quanex") and Temroc Metals, Inc., a corporation ("Temroc"),

                              W I T N E S S E T H:

                  WHEREAS, Temroc maintains the Temroc Metals, Inc.
Non-Bargaining Unit Employees 401(k) Plan (the "Prior Plan") and its related
trust (the "Prior Trust") for the benefit of its employees and their
beneficiaries;

                  WHEREAS, Quanex maintains the Nichols 401(k) Savings Plan (the
"Plan") and its related trust (the "Trust");

                  WHEREAS, the Plan provides that any business organization may,
with the approval of Quanex, adopt the Plan and Trust for all or any
classification of its employees;

                  WHEREAS, Temroc desires to merge the Prior Plan into the Plan,
and to merge the Prior Trust into the Trust, with Fidelity Management Trust
Company, as trustee of the Trust (the "Trustee"), all effective as of the close
of business on July 1, 2001;

                  WHEREAS, Temroc, in connection with the mergers, desires to
adopt the Plan and Trust, and Quanex desires to consent to the adoptions; and

                  WHEREAS, as a result of the mergers, Temroc shall become an
adopting employer of the Plan and Trust;

                  NOW, THEREFORE, the parties hereto agree as follows:

<PAGE>   2

                      ADOPTION OF PLAN AND TRUST BY TEMROC

         (1) ADOPTION. Temroc hereby adopts the Plan and Trust, effective as of
July 1, 2001, for all of its employees who are not included in a unit of
employees covered by a collective bargaining agreement and who otherwise qualify
as members therein under the terms and provisions of the Plan and Trust, and
hereby agrees to be bound by all the terms, provisions, limitations, and
conditions of the Plan and Trust with respect to the employees eligible for
membership in the Plan to the same extent as if it had executed identical plan
and trust documents, except that, effective July 1, 2001, the Plan shall be
amended as follows:

                  (a) RETIREMENT AGE. Section 1.39 shall be amended to add the
         following sentence immediately following the second sentence of such
         section: In the case of a Member or former Member who was a participant
         in the Temroc Metals, Inc. Non-Bargaining Unit Employees 401(k) Plan
         (the "Temroc Plan"), "Retirement Age" means the time he attains age 65
         if that definition is more favorable for him than the definition in the
         first sentence of this Section 1.39.

                  (b) ELIGIBILITY. Section 3.01 of the Plan shall be amended to
         add the following sentence immediately following the last sentence of
         such section: Each Employee who is employed by Temroc Metals, Inc.
         ("Temroc") and was a participant in the Temroc Plan on June 30, 2001
         shall be eligible to participate in the Plan on July 1, 2001.

                  (c) LOANS. Section 6.07 of the Plan shall be amended to add
         the following sentence immediately following the last sentence of such
         section: This Section 6.07 shall not be effective with respect to
         Members who are employed by Temroc until January1, 2002.


                                       2
<PAGE>   3

         (2) CONSENT. Quanex hereby consents to and approves the adoption of the
Plan by Temroc, effective as of July 1, 2001.

         (3) COMMINGLING OF FUNDS. Temroc further agrees that the Committee, in
its sole discretion, may permit the funds contributed by them to be commingled
for purposes of investment with other funds in the Trust or to be maintained
separately.

         (4) AGREEMENT TO FURNISH INFORMATION. Temroc agrees to promptly furnish
all information required by the Committee and the Trustee with reference to its
employees who are eligible for the Plan, and to pay its contribution to the Plan
the first Plan Year and all subsequent Plan Years in which it is an adopting
employer of the Plan, in the amount and at the time required by the terms of the
Plan.

                     MERGER OF THE PRIOR PLAN INTO THE PLAN

         (1) MERGER OF PLAN. Effective July 1, 2001, the Prior Plan is merged
into the Plan.

         (2) ELIGIBILITY. No person who is not a participant in the Prior Plan
on June 30, 2001, shall be eligible to become a participant in the Prior Plan.

         (3) CONTRIBUTIONS. No contributions shall be made under the Prior Plan
with respect to any period after June 30, 2001.

         (4) QUALIFICATION A CONDITION PRECEDENT TO MERGER. The merger of the
Prior Plan into the Plan is contingent upon and subject to the express condition
precedent that the merger meets all statutory and regulatory requirements for
qualification of the Plan and the Prior Plan and their related trusts have at
all times in form and in operation maintained their qualified and exempt status.
In the event that this condition precedent is not satisfied the merger shall
fail retroactively for failure to meet the condition precedent and the portion
of the Plan trust fund


                                       3
<PAGE>   4

attributable to the Prior Plan assets shall be immediately returned to Temroc
and the merger shall be void ab initio.


         (5) COMPLIANCE WITH SECTIONS 411(d)(6) AND 414(l) OF THE INTERNAL
REVENUE CODE OF 1986. The merger of the Prior Plan into the Plan will comply
with sections 411(d)(6) and 414(l) of the Internal Revenue Code of 1986, as
amended (the "Code"). The distribution options available under the Prior Plan
shall be preserved in the Plan in accordance with section 411(d)(6) of the Code.
Each participant in the Prior Plan would (if the Prior Plan then terminated)
receive a benefit immediately after the merger equal to or greater than the
benefit he would have been entitled to receive immediately before the merger (if
the Prior Plan had then terminated).

         (6) SINGLE PLAN. Upon the merger of the Prior Plan into the Plan, the
Prior Plan and the Plan will be a single plan within the meaning of section
414(l) of the Code. All Prior Plan and Plan assets will be available to pay the
benefits of all participants in the Prior Plan and Plan.


                                       4

<PAGE>   5
                  IN WITNESS WHEREOF, the parties have caused this Agreement to
be executed on this 26th day of June, 2001.


                                      QUANEX CORPORATION


                                      By           /s/ Terry Murphy
                                        ---------------------------------------
                                      Title        VP Finance & CFO
                                           ------------------------------------


                                      TEMROC METALS, INC.


                                      By           /s/ Terry Murphy
                                        ---------------------------------------
                                      Title            VP Finance
                                           ------------------------------------