SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549




FORM 11-K



[X]      Annual report pursuant to Section 15(d) of the Securities Exchange Act
         of 1934

         For the fiscal year ended December 31, 2001

         Commission File Number 1-5725

         A.       Full title of the plan and the address of the plan, if
                  different from that of the issuer named below:

                  Piper Impact 401 (k) Plan

         B.       Name of the issuer of the securities held pursuant to the plan
                  and the address of its principal executive office:

                  Quanex Corporation
                  1900 West Loop South, Suite 1500
                  Houston, TX 77027





                          INDEPENDENT AUDITORS' REPORT


The Benefits Committee
Quanex Corporation
Houston, Texas

Re: Piper Impact 401(k) Plan

We have audited the accompanying statements of net assets available for benefits
of the Piper Impact 401(k) Plan ("the Plan") as of December 31, 2001 and 2000,
and the related statements of changes in net assets available for benefits for
the years then ended. These financial statements are the responsibility of the
Plan's management. Our responsibility is to express an opinion on these
financial statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States of America. Those standards require that we plan and
perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement. An audit includes examining, on a
test basis, evidence supporting the amounts and disclosures in the financial
statements. An audit also includes assessing the accounting principles used and
significant estimates made by management, as well as evaluating the overall
financial statement presentation. We believe that our audits provide a
reasonable basis for our opinion.

In our opinion, such financial statements present fairly, in all material
respects, the net assets available for benefits of the Plan as of December 31,
2001 and 2000, and the changes in net assets available for benefits for the
years then ended in conformity with accounting principles generally accepted in
the United States of America.

Our audits were conducted for the purpose of forming an opinion on the basic
financial statements taken as a whole. The accompanying supplemental schedule of
investments as of December 31, 2001 is presented for the purpose of additional
analysis and is not a required part of the basic financial statements but is
supplementary information required by the Department of Labor's Rules and
Regulations for Reporting and Disclosure under the Employee Retirement Income
Security Act of 1974. The supplemental schedule is the responsibility of the
Plan's management. This supplemental schedule has been subjected to the auditing
procedures applied in our audits of the basic financial statements and, in our
opinion, are fairly stated in all material respects when considered in relation
to the basic financial statements taken as a whole.

/s/ DELOITTE & TOUCHE, LLP
- --------------------------
DELOITTE & TOUCHE, LLP

Houston, Texas
June 19,2002





                               QUANEX CORPORATION
                            PIPER IMPACT 401(k) PLAN

                 STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS


<Table>
<Caption>
                                                            DECEMBER 31,
                                                       -----------------------
                                                          2001         2000
                                                       ----------   ----------
                                                              
Assets:
              Investments at fair value (see Note C)   $7,050,373   $6,913,217

              Participant loans                           424,617      365,313

              Employee contributions receivable            64,502       83,617
              Employer contributions receivable            40,373       46,464
                                                       ----------   ----------
                                                          104,875      130,081
                                                       ----------   ----------

Net assets available for benefits                      $7,579,865   $7,408,611
                                                       ==========   ==========
</Table>



                       See notes to financial statements.





                               QUANEX CORPORATION
                            PIPER IMPACT 401(k) PLAN

                  STATEMENTS OF CHANGES IN NET ASSETS AVAILABLE
                                  FOR BENEFITS


<Table>
<Caption>
                                                                       DECEMBER 31,
                                                               ----------------------------
                                                                   2001            2000
                                                               ------------    ------------
                                                                         
Investment income:
              Interest and dividends                           $    138,081    $    539,795
              Net appreciation  (depreciation) in fair value
                of investments (see Note C)                        (800,919)       (862,632)
                                                               ------------    ------------
                                                                   (662,838)       (322,837)
                                                               ------------    ------------

Contributions:
              Employer (net of forfeitures)                         503,960         463,148
              Employee                                              969,125         958,451
                                                               ------------    ------------
                                                                  1,473,085       1,421,599
                                                               ------------    ------------

Interest on participant loans                                        33,672          24,362
                                                               ------------    ------------
                   Total additions                                  843,919       1,123,124
                                                               ------------    ------------

Benefit payments                                                    666,657       1,586,931
Administrative fees (see Note D)                                      6,008           5,643
                                                               ------------    ------------
                   Total deductions                                 672,665       1,592,574
                                                               ------------    ------------

Increase (decrease) in net assets available
  for benefits                                                      171,254        (469,450)

Net assets available for benefits:
              Beginning of year                                   7,408,611       7,878,061
                                                               ------------    ------------
              End of year                                      $  7,579,865    $  7,408,611
                                                               ============    ============
</Table>



                       See notes to financial statements.





         SCHEDULE OF ASSETS HELD FOR INVESTMENT PURPOSES AT END OF YEAR
                             EIN: 38-1872178; PN 001

                               QUANEX CORPORATION
                            PIPER IMPACT 401(k) PLAN

                      SUPPLEMENTAL SCHEDULE OF INVESTMENTS
                                December 31, 2001

<Table>
<Caption>
                                                              Shares/                   Current
                                                             Par Value       Cost        Value
                                                             ----------   ----------   ----------
                                                                              
*   Fidelity Puritan Fund                                        38,450   $  718,739   $  679,418
*   Fidelity Magellan Fund                                        1,698      206,398      176,970
*   Fidelity Contrafund                                          23,642    1,191,856    1,011,186
*   Fidelity Growth & Income Fund                                 1,418       58,886       52,989
*   Fidelity Independence Fund                                   30,800      627,398      485,713
*   Fidelity Overseas Fund                                          717       25,580       19,649
*   Fidelity Balanced Fund                                        4,130       63,861       61,530
*   Fidelity Blue Chip Fund                                      56,411    2,554,955    2,422,274
*   Fidelity Asset Manager Fund                                  21,676      373,838      335,978
*   Fidelity Low-Priced Stock Fund                                3,777       96,915      103,560
*   Fidelity Government Money Market Fund                       798,918      798,918      798,918
    Templeton Foreign Fund                                          938        8,983        8,676
    Neuberger & Berman Partners Trust Fund                          102        1,775        1,635
                                                                          ----------   ----------
                Total Mutual Fund Assets                                   6,728,102    6,158,496

*   Quanex Corporation unitized common stock                     25,870      257,338      342,520
*   Fidelity Common/Commingled trust                            549,357      549,357      549,357
    Participant loans (bearing interest rates from
       8.75% to 10.50%, maturing within five to ten years)                   424,617      424,617
                                                                          ----------   ----------
                Total Investments                                         $7,959,414   $7,474,990
                                                                          ==========   ==========
</Table>



* Party-in-Interest





                               QUANEX CORPORATION
                            PIPER IMPACT 401(k) PLAN

                          NOTES TO FINANCIAL STATEMENTS
                     YEARS ENDED DECEMBER 31, 2001 AND 2000



A.       DESCRIPTION OF THE PLAN

         The following description of the Piper Impact 401(k) Plan (the "Plan")
         provides only general information. Participants should refer to the
         Plan document for a more complete description of the Plan's provisions.

         (1)      General. The Plan is a defined contribution plan which covers
                  substantially all full-time employees of Piper Impact, a
                  division of Quanex Corporation (the "Company"). The Plan is
                  subject to the provisions of the Employee Retirement Income
                  Security Act of 1974 ("ERISA"). The assets of the Plan are
                  held in trust by Fidelity Management Trust Company ("Fidelity"
                  or the "Trustee"). The Benefits Committee (the "Committee"),
                  appointed by Quanex Corporation's Board of Directors, serves
                  as the Plan administrator.

         (2)      Contributions. Beginning January 1, 2002, participants may
                  contribute to the Plan by electing salary deferrals up to 50%
                  of compensation (20% before January 1, 2002) as defined by the
                  Plan document. The Company contributes 25% of the first 6% of
                  base compensation that a participant contributes to the Plan.
                  Contributions are subject to certain limitations. In addition,
                  the Company makes a contribution on behalf of employees with
                  at least three months of service, based on company profits and
                  calculated based on a percentage of the employee's
                  compensation.

         (3)      Participant Accounts. Each participant's account is credited
                  with the participant's contribution and allocations of the
                  Company's contribution and Plan earnings, and charged with an
                  allocation of administrative expenses. Allocations are based
                  on participant earnings or account balances, as defined. The
                  benefit to which a participant is entitled is the benefit that
                  can be provided from the participant's vested account.

         (4)      Vesting. Participants are immediately vested in their
                  contributions and earnings thereon. Vesting in the Company's
                  matching and discretionary contribution portion of their
                  accounts plus actual earnings thereon is based on years of
                  continuous service. A participant is 20% vested for each year
                  of credited service beginning with his or her second year and
                  is 100% vested after six years of credited service. Forfeited
                  balances of terminated participants' non-vested accounts are
                  used to reduce current or future Company contributions.
                  Amounts forfeited during 2001 and 2000 were $39,858 and
                  $58,072, respectively.

         (5)      Payment of Benefits. The Plan is intended for long-term
                  savings but provides for early withdrawals and loan
                  arrangements under certain conditions. In accordance with the
                  Code, upon termination of service, a participant may elect to
                  receive a lump-sum distribution equal to the total amount of
                  vested benefits in his or her account. Terminated participants
                  with an account balance of less than $5,000 will automatically
                  receive a lump sum distribution.

         (6)      Loans. Loans may be granted to a participant of the Plan at
                  the Committee's discretion. Loan terms range up to five years
                  or ten years if used for the purchase of a primary residence.
                  The loans bear a reasonable rate of interest established by
                  the Committee. Interest on the loan is allocated to the
                  borrower's participant account.


B.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

         (1)      Accounting Basis. The financial statements of the Plan are
                  prepared on the accrual basis of accounting in accordance with
                  generally accepted accounting principles.





         (2)      Investment Valuation. The Plan recognizes net appreciation or
                  depreciation in the fair value of its investments. Investments
                  are reflected at fair value in the financial statements. Fair
                  value of mutual fund assets is determined using a quoted net
                  asset value. Fair value for Quanex Corporation common stock,
                  which is listed on the New York Stock Exchange, is determined
                  by using the last recorded sales price. The recorded value of
                  the common/commingled trust is at face value, which is fair
                  value.

         (3)      Use of Estimates. The preparation of financial statements in
                  conformity with generally accepted accounting principles
                  requires management to make estimates and assumptions that
                  affect the reported amounts of assets and liabilities and
                  changes therein and disclosure of contingent assets and
                  liabilities. Actual results could differ from these estimates.

         (4)      Administrative Expense. The Company pays all administrative
                  expenses, except for loan set up and carrying fees and
                  redemption fees imposed on certain Fidelity funds.

         (5)      Payments of Benefits. Benefit payments are recorded when paid.

C.       INVESTMENTS

         The following are investments that represent 5 percent or more of the
         Plan's net assets.

<Table>
<Caption>
                                           December 31, 2001         December 31, 2000
                                          Shares       Amount       Shares       Amount
                                        ----------   ----------   ----------   ----------
                                                                   
Fidelity Puritan Fund                       38,450   $  679,418       28,833   $  542,932
Fidelity Contrafund                         23,642    1,011,186       22,437    1,103,233
Fidelity Independence Fund                  30,800      485,713       30,116      662,856
Fidelity Blue Chip Fund                     56,411    2,422,274       52,140    2,686,750
Fidelity Government Money Market Fund      798,918      798,918      654,507      654,507
Fidelity Common/Commingled Trust           549,357      549,357      414,834      414,834
</Table>

         During the years ended December 31, 2001 and 2000, the Plan's
         investments (including gains and losses on investments bought and sold,
         as well as held during the year) appreciated / (depreciated) in value
         as follows:

<Table>
<Caption>
                                  2001          2000
                               ----------    ----------
                                       
Mutual funds                   $ (894,858)   $ (841,485)
Quanex unitized common stock       93,939       (21,147)
                               ----------    ----------
                               $ (800,919)   $ (862,632)
                               ==========    ==========
</Table>

D.       RELATED PARTY TRANSACTIONS

         Certain Plan investments are shares of mutual funds managed by
         Fidelity. Fidelity is the trustee as defined by the Plan and,
         therefore, these transactions qualify as party-in-interest
         transactions. Fees paid by the Plan for the investment management
         services amounted to $6,008 and $5,643 for the years ended December 31,
         2001 and 2000, respectively. In addition, the Plan invests in shares of
         Quanex Corporation unitized common stock. Quanex Corporation is the
         Plan sponsor as defined by the Plan and, therefore, these transactions
         also qualify as party-in-interest transactions. As of December 31, 2001
         and 2000, the value of Quanex Corporation unitized common stock held by
         the Plan was $342,520 and $217,783, respectively.

E.       PLAN TERMINATION

         Although it has not expressed any intention to do so, the Company has
         the right under the Plan to terminate the Plan at any time subject to
         the provisions set forth in ERISA. In the event of Plan termination,
         the assets held by the Trustee under the Plan will be valued and fully
         vested, and each participant will be entitled to distributions
         respecting his or her account.





F.       FEDERAL INCOME TAX STATUS

         The Plan is subject to specific rules and regulations related to
         employee benefit plans under the Department of Labor and the Internal
         Revenue Service. The Plan has received a favorable letter of tax
         determination dated September 30, 1998. As such, the Plan is a
         qualified trust under Sections 401(a) and 401(k) of the Internal
         Revenue Code (the "Code") and, as a result, is exempt from federal
         income tax under Section 501(a) of the Code. The Company believes the
         Plan is currently designed and being operated in compliance with the
         applicable requirements of the Code. The Company believes the Plan was
         qualified and the related trust was tax-exempt as of the financial
         statement dates.





                                   SIGNATURES




The Plan. Pursuant to the requirements of the Securities Exchange Act of 1934,
the trustees (or other persons who administer the employee benefit plan) have
duly caused this annual report to be signed on its behalf by the undersigned
hereunto duly authorized.




                                       Piper Impact 401 (k) Plan


Date:  June 28, 2002                   /s/ Viren M. Parikh
                                       -------------------
                                       Viren M. Parikh, Benefits Committee





                                INDEX TO EXHIBITS


<Table>
<Caption>
EXHIBIT
NUMBER                  DESCRIPTION
- -------                 -----------
                     
23.1                    Independent Auditor's Consent
</Table>