<PAGE>   1
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D. C. 20549

                                 FORM 10-K / A-1

            (X) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended August 31, 1996          Commission file number 1-9967
                          ---------------                                 ------

                          AMCAST INDUSTRIAL CORPORATION
             (Exact name of registrant as specified in its charter)


                        OHIO                         31-0258080
            ---------------------------      ------------------------
              (State of Incorporation)            (I.R.S. employer
                                                  identification no.)

7887 Washington Village Drive, Dayton, Ohio                                45459
--------------------------------------------------------------------------------
(Address of principal executive officers)                             (Zip Code)


                            291-7000 (Area Code 937)
--------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)

           Securities registered pursuant to Section 12(b) of the Act:

                                                         Name of Each Exchange
      Title of Each Class                                 on Which Registered
      -------------------                                 -------------------
Common Shares, without par value                        New York Stock Exchange
Preferred Share Purchase Rights


           Securities registered pursuant to Section 12(g) of the Act:

                                      NONE

     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 and 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months, and (2) has been subject to such filing
requirements for the past 90 days. Yes  X    No
                                       ---      --- 

     Aggregate market value of common stock, no par value, held by
non-affiliates of the registrant (assuming only for the purposes of this
computation that directors and officers may be affiliates) as of October 21,
1996 -- $163,163,072.

     Number of common shares outstanding, without par value, as of October 21,
1996 -- 8,618,491 shares.

                       DOCUMENTS INCORPORATED BY REFERENCE

     Part IV -- Index to exhibits at page 4 of this report.
<PAGE>   2
                                    STATEMENT
                                    ---------

Amcast Industrial Corporation is filing this Form 10-K/A-1 for the purpose of
amending Exhibit 3.1 contained on pages 21 through 35 of its Annual Report on
Form 10-K for the year ended August 31, 1996. Pages 34 and 35 were inadvertently
omitted from the filing.


PART IV, ITEM 14 - EXHIBITS
---------------------------

a)       Documents filed as part of this report:

         1.       Exhibits - See Index to Exhibits (page 4 hereof).


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<PAGE>   3
                                   SIGNATURES


       Pursuant to the requirements of Section 13 of the Securities Exchange Act
of 1934, the registrant has duly caused this report to be signed on its behalf
by the undersigned, thereunto duly authorized, on the 9th day of December 1996.



                                         AMCAST INDUSTRIAL CORPORATION
                                         (Registrant)

                                     By       /s/ John H. Shuey
                                         ------------------------------------
                                         John H. Shuey
                                         President and
                                         Chief Executive Officer

         Pursuant to the requirements of the Securities and Exchange Act of
1934, this report has been signed below by the following persons on behalf of
the registrant and in the capacities indicated.

<TABLE>
<CAPTION>
    Signature                                     Title                              Date
----------------                             -----------------                  -----------------

<S>                                     <C>                                     <C>
/s/ John H. Shuey                       President, Chief Executive              December 9, 1996
-------------------------------         Officer, Director            
John H. Shuey                           (Principal Executive Officer)
                                        

/s/ Douglas D. Watts                    Vice President, Finance                 December 9, 1996
-------------------------------         (Principal Financial Officer)
Douglas D. Watts                        

/s/ William L. Bown                     Vice President and Controller           December 9, 1996
-------------------------------         (Principal Accounting Officer)
William L. Bown                         

*Leo W. Ladehoff                        Chairman of the Board,
                                        Director                                December 9, 1996
*James K. Baker                         Director                                December 9, 1996
*Walter E. Blankley                     Director                                December 9, 1996
*Peter H. Forster                       Director                                December 9, 1996
*Ivan W. Gorr                           Director                                December 9, 1996
*Earl T. O'Loughlin                     Director                                December 9, 1996
*William G. Roth                        Director                                December 9, 1996
*R. William Van Sant                    Director                                December 9, 1996
</TABLE>


         *The undersigned John H. Shuey, by signing his name hereto, does sign
and execute this amendment to the annual report on Form 10-K/A-1 on behalf of
each of the above-named directors of the registrant pursuant to powers of
attorney executed by each such director and filed with the Securities and
Exchange Commission as an exhibit to the Form 10-K.


                                            By    /s/ John H. Shuey
                                              _________________________________
                                                John H. Shuey
                                                Attorney in Fact


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<PAGE>   4
                                INDEX OF EXHIBITS
                                -----------------

<TABLE>
<CAPTION>
Exhibit                                                                                 Located at
Number                                Description                                      Numbered Page
---------         ---------------------------------------------------                  -------------

<S>               <C>                                                                            <C>
     3            ARTICLES OF INCORPORATION AND BY-LAWS:

                  3.1  Articles of Incorporation of Amcast Industrial
                       Corporation.                                                              **

                  3.2  Code of Regulations of Amcast Industrial
                       Corporation.                                                              *

     4            INSTRUMENTS DEFINING THE RIGHTS OF SECURITY
                  HOLDERS, INCLUDING INDENTURES:

                  4.1  $60,000,000 amended and restated Revolving Credit
                       Agreement between Amcast Industrial Corporation and Star
                       Bank, The First National Bank of Chicago, Bank One,
                       Dayton, NA, Society National Bank, and National Bank of
                       Detroit dated June 7, 1995 - incorporated by reference
                       from Form 10-K for the year ended August 31, 1995.

                  4.2  Loan Agreement between the City of Elkhart, Indiana,
                       and Elkhart Products Corporation, dated as of February
                       1, 1988, for $2,050,000, Economic Development
                       Revenue Refunding Bonds, Series 1988.                                     +

                  4.3  $10,000,000 Senior Note Agreement between
                       Amcast Industrial Corporation and Principal
                       Mutual Life Insurance Company dated
                       September 1, 1989, as amended.                                            *

                  4.4  Amendment Agreement, dated July 24, 1995, to the
                       $10,000,000 Senior Note Agreement between Amcast
                       Industrial Corporation and Principal Mutual Life
                       Insurance Company, dated September 1, 1989 -
                       incorporated by reference from Form 10-K for the year
                       ended August 31, 1995.

                  4.5  Loan Agreement by and between the City of Fayetteville,
                       Arkansas, and Amcast Industrial Corporation, dated as of
                       December 1, 1991, for $5,050,000 City of Fayetteville,
                       Arkansas, variable/fixed rate demand Industrial
                       Development Revenue Refunding Bonds, Series 1992.                         +

                  4.6  Lease Agreement between PNC Leasing Corp., lessor, and
                       Amcast Industrial Corporation, lessee, dated July 15,
                       1992 incorporated by reference from Form 10-K for the
                       year ended August 31, 1993.
</TABLE>


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<PAGE>   5
                           INDEX TO EXHIBITS (cont'd)


<TABLE>
<CAPTION>
Exhibit                                                                                 Located at
Number                                Description                                      Numbered Page
---------         ---------------------------------------------------                  -------------

<S>               <C>                                                                            <C>
                  4.7   Lease Agreement between PNC Leasing Corp., lessor,
                        and Amcast Industrial Corporation, lessee, dated
                        August 8, 1996.                                                          +

                  4.8   Amcast guarantee of $15,000,000 of the $25,000,000
                        Credit and Intercreditor Agreement between Casting
                        Technology Company (a joint venture partnership between
                        Amcast Industrial Corporation and Izumi Industries,
                        Ltd.) and National Bank of Detroit and The Asahi Bank,
                        Ltd., and a copy of the Creditor and Intercreditor
                        Agreement, dated July 28, 1995 - incorporated by
                        reference from Form 10-K for the year ended August 31,
                        1995.

                  4.9   Amendment Agreement, dated January 5, 1996, to the
                        $25,000,000 Credit and Intercreditor Agreement between
                        Casting Technology Company and National Bank of
                        Detroit and The Asahi Bank, Ltd., dated July 28, 1995.                   *

                  4.10  Amendment Agreement, dated May 31, 1996, to the
                        $25,000,000 Credit and Intercreditor Agreement between
                        Casting Technology Company and National Bank of Detroit
                        and The Asahi Bank, Ltd., dated July 28, 1995, and
                        amended Guarantee Agreement which increased Amcast's
                        guarantee to $21,000,000 of the revised credit amount
                        of $35,000,000.                                                          *

                  4.11  $50,000,000 Note Agreement between Amcast Industrial
                        Corporation and Principal Mutual Life Insurance Company
                        and The Northern Mutual Life Insurance Company, dated
                        November 1, 1995 - incorporated by reference from Form
                        10-K for the year ended August 31, 1995.

    10            MATERIAL CONTRACTS:

                  10.1  Amcast Industrial Corporation Employee Share-
                        builder Plan effective August 26, 1987.                                  *

                  10.2  Amcast Industrial Corporation Annual Incentive
                        Plan effective September 1, 1982.                                        *

                  10.3  Deferred Compensation Agreement for Directors
                        of Amcast Industrial Corporation.                                        *

                  10.4  Executive Agreement between Amcast Industrial
                        Corporation and Leo W. Ladehoff, Chairman of the Board
                        and former Chief Executive Officer of the Company,
                        dated March 3, 1995-incorporated by reference from Form
                        10-Q for the quarter ended May 28, 1995.
</TABLE>


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<PAGE>   6
                           INDEX TO EXHIBITS (cont'd)
                           --------------------------


<TABLE>
<CAPTION>
Exhibit                                                                                 Located at
Number                                Description                                      Numbered Page
---------         ---------------------------------------------------                  -------------

<S>              <C>                                                                             <C>
                 10.5    Indemnification Agreement for Directors of
                         Amcast Industrial Corporation, effective
                         October 30, 1987.                                                       *

                 10.6    First Master Benefit Trust Agreement between
                         Amcast Industrial Corporation and Bank One,
                         Dayton, NA, effective March 11, 1988.                                   *

                 10.7    Amcast Industrial Corporation 1989 Stock
                         Incentive Plan, effective October 19, 1988 -
                         as amended, effective December 9, 1992 -
                         incorporated by reference from Form 10-Q
                         for the quarter ended February 28, 1994.

                 10.8    Amcast Industrial Corporation 1989 Director
                         Stock Option Plan, effective October 19, 1988.                          *

                 10.9    Amcast Industrial Corporation Change of Control
                         Agreements effective September 1, 1996.                                 *

                 10.10   Amcast Industrial Corporation Long-Term Incentive Plan
                         effective September 1, 1991-incorporated by reference
                         from Form 10-K for the year ended August 31, 1992.

                 10.11   Amcast Industrial Corporation Nonqualified
                         Supplementary Benefit Plan, effective May 29, 1991 -
                         incorporated by reference from Form 10-K for the year
                         ended August 31, 1994.

                 10.12   Change of Control Agreement between Amcast Industrial
                         Corporation and John H. Shuey, Chief Executive Officer,
                         effective August 14, 1995-incorporated by reference
                         from Form 10-K for the year ended August 31, 1995.

    13           ANNUAL REPORT TO SECURITY HOLDERS:

                 13.1    Amcast Industrial Corporation Annual Report to
                         Shareholders for year ended August 31, 1996. Those
                         portions of the Annual Report as are specifically
                         referenced under Parts I, II, and IV of
                         this report are filed herein.                                           *
</TABLE>


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<PAGE>   7
                           INDEX TO EXHIBITS (cont'd)
                           --------------------------


<TABLE>
<CAPTION>
Exhibit                                                                                 Located at
Number                                Description                                      Numbered Page
---------         ---------------------------------------------------                  -------------

<S>               <C>                                                               <C>
    21            SUBSIDIARIES OF THE REGISTRANT:

                  Amcast Industrial Corporation has ten wholly-owned
                  subsidiaries which are included in the consolidated financial
                  statements of the Company. Information regarding these
                  subsidiaries is set forth below:

                  Amcast Industrial Limited
                  Jurisdiction of Incorporation:                                    Ontario, Canada                     
                  Name Under Which Business Is Done:                                Amcast Industrial Limited          
                                                                                                                       
                  Elkhart Products Corporation                                                                         
                  Jurisdiction of Incorporation:                                    Indiana                            
                  Name Under Which Business Is Done:                                Elkhart Products Corporation       
                                                                                                                       
                  WheelTek, Inc.                                                                                       
                  Jurisdiction of Incorporation:                                    Indiana                            
                  Name Under Which Business Is Done:                                WheelTek, Inc. and Amcast          
                                                                                    Automotive Wheel Division          
                  Amcast Precision Products, Inc.                                                                      
                  Jurisdiction of Incorporation:                                    California                         
                  Name Under Which Business Is Done:                                Amcast Precision Products, Inc.    
                                                                                                                       
                  Amcast Investment Services Corporation                                                               
                  Jurisdiction of Incorporation:                                    Delaware                           
                  Name Under Which Business Is Done:                                Amcast  Investment Services        
                                                                                    Corporation                        
                  Amcast Industrial Financial Services, Inc.                                                           
                  Jurisdiction of Incorporation:                                    Ohio                               
                  Name Under Which Business is Done:                                Amcast Industrial                  
                                                                                      Financial Services, Inc.         
                  Amcast Industrial Sales Corporation                                                                  
                  Jurisdiction of Incorporation:                                    U.S. Virgin Islands                
                  Name Under Which Business is Done:                                Amcast Industrial Sales Corporation
                                                                                                                       
                  Amcast Automotive, Inc.                                                                              
                  Jurisdiction of Incorporation:                                    Michigan                           
                  Name Under Which Business is Done:                                Amcast Automotive, Inc.            
                                                                                                                       
                  Flagg Brass, Inc.                                                                                    
                  Jurisdiction of Incorporation:                                    Ohio                               
                  Name Under Which Business is Done:                                Flagg Brass, Inc.                  
                                                                                                                       
                  Amcast Casting Technologies, Inc.                                                                    
                  Jurisdiction of Incorporation:                                    Indiana                            
                  Name Under Which Business is Done:                                Amcast Casting Technologies, Inc.  
</TABLE>


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<PAGE>   8
                           INDEX TO EXHIBITS (cont'd)
                           --------------------------


<TABLE>
<CAPTION>
Exhibit                                                                                 Located at
Number                                Description                                      Numbered Page
---------         ---------------------------------------------------                  -------------

<S>               <C>                                                                            <C>
    23            CONSENTS OF EXPERTS AND COUNSEL:

                  23.1   Consent of Ernst & Young LLP dated
                         November 22, 1996, with respect to the
                         incorporation by reference of
                         their report dated October 8, 1996 into this
                         Annual Report (Form 10-K), the inclusion of the
                         financial statement schedule listed in Item 14(a)(2)
                         to the financial statements covered by their report
                         dated October 8, 1996, and material incorporated by
                         reference into Amcast Industrial Corporation's
                         Post-Effective Amendment No. 1 to Registration
                         Statement No. 33-2876 on Form S-8, on Registration
                         Statements on Form S-8 (Registration Nos. 33-18690,
                         33-28080, 33-28084, 33-38176, 33-61290 and 333-00133),
                         and on Registration Statement No. 33-28075 on
                         Form S-3                                                                *

    24            POWER OF ATTORNEY:

                  24.1   Powers of attorney of persons who are indicated
                         as having executed this Annual Report Form 10-K
                         on behalf of another.                                                   *

    27            FINANCIAL DATA SCHEDULE:

                  27.1   Article 5 of Regulation S-X Financial Data Schedule
                         Form 10-K for the year ended August 31, 1996                            *
</TABLE>



+   Indicates that the document relates to a class of indebtedness that does not
    exceed 10% of the total consolidated assets of the Company and that the
    Company will furnish a copy of the document to the Commission upon its
    request.


*   Incorporated by reference from Form 10-K for the year ended August 31, 1996.

**  Amended exhibit to Form 10-K for the year ended August 31, 1996 is enclosed
    herein, beginning on page 9.


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