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

                                   FORM 10-Q
                                 Amendment #1


 X   QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES AND
---                                                                        
     EXCHANGE ACT OF 1934
     For the quarterly period ended September 30, 1996

     or

     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
---                                                                     
     AND EXCHANGE ACT OF 1934
     For the transition period from ____________________ to ____________________

                          Commission File No. 0-13059

                                CERADYNE, INC.
--------------------------------------------------------------------------------
      (Exact name of Registrant as specified in its charter)


           Delaware                                        33-0055414
-------------------------------------                 --------------------------
(State or other jurisdiction of                       (I.R.S. Employer 
incorporation or organization)                        Identification No.) 
 
 3169 Redhill Avenue, Costa Mesa, CA                    92626
-------------------------------------                 --------------------------
  (Address of principal executive)                    (Zip Code)
 
Registrant's telephone number, including area code  (714) 549-0421

                                      N/A
--------------------------------------------------------------------------------
(Former name, former address and former fiscal year, if changed since last 
report)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

               YES   X                   NO 
                   -----                    -----

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

          Class                           Outstanding at September 30, 1996
----------------------------          -----------------------------------------
Common Stock, $.01 par value                      7,834,190 Shares


                                      
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<TABLE>
<CAPTION>
 
                                CERADYNE, INC.
                          CONSOLIDATED BALANCE SHEETS
                     LIABILITIES AND SHAREHOLDERS' EQUITY
                   (AMOUNTS IN THOUSANDS, EXCEPT SHARE DATA)

                                               9-30-1996    12-31-1995
                                              (UNAUDITED)   (AUDITED)
=======================================================================
<S>                                           <C>           <C> 
CURRENT LIABILITIES:
 
  Current portion of long-term debt           $      464    $     1,601
 
  Accounts payable                            $    1,494    $     1,642
 
  Accrued expenses:
 
    Payroll and payroll related               $      846    $       588
 
    Other                                     $      333    $       381
                                              ----------    -----------
 
  Total current liabilities                   $    3,137    $     4,212
                                              ----------    -----------
 
LONG-TERM DEBT                                $      555    $       555
                                              ----------    -----------
 
DEFERRED REVENUE                              $      261    $       261
                                              ----------    -----------
 
SHAREHOLDERS' EQUITY:
 
  Common stock, $.01 par value:
    Authorized - 12,000,000 shares;
    Outstanding - 7,834,190 shares &
    7,715,624 shares at 9-30-1996 &
    12-31-1995, respectively                  $   36,967    $    36,590
 
  Accumulated deficit                         $  (13,938)   $   (16,738)
                                              ----------    -----------
 
  TOTAL SHAREHOLDERS' EQUITY                  $   23,029    $    19,852
                                              ----------    -----------
TOTAL LIABILITIES & SHAREHOLDERS' EQUITY      $   26,982    $    24,880
                                              ==========    ===========
=======================================================================

</TABLE>

                      SEE ACCOMPANYING CONDENSED NOTES TO
                      CONSOLIDATED FINANCIAL STATEMENTS.

                                       5
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Items 2, 3 and 5.  Not applicable

Item 6.  Exhibits and Reports on Form 8-K
         --------------------------------

(a)  Financial Data Schedule:

     None

(b)  Reports on Form 8-K:

     None

SIGNATURE
---------

Pursuant to the requirements 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.

CERADYNE, INC.



By:  /s/ Howard F. George  
     ----------------------------------------------------
     Howard F. George
     Vice President
     Chief Financial Officer
     (Principal Financial and Accounting Officer)

Dated:  November 20, 1996

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