Exhibit 5.1

                     [LETTERHEAD OF YOCCA CARLSON & RAUTH]




                                 June 26, 2001

Ceradyne, Inc.
3169 Redhill Avenue
Costa Mesa, California  92626

     Re:  Registration Statement on Form S-8 1994 Stock Incentive Plan

Ladies and Gentlemen:

     We have acted as counsel for Ceradyne, Inc., a Delaware corporation (the
"Company"), in connection with the preparation of a Registration Statement on
Form S-8 (the "Registration Statement") which the Company intends to file with
the Securities and Exchange Commission pursuant to the Securities Act of 1933,
as amended (the "Act").  The Registration Statement relates to an additional
150,000 shares of the Company's Common Stock, $.01 par value (the "Shares"),
which may be issued and sold by the Company upon the exercise of options granted
and to be granted under the Ceradyne, Inc. 1994 Stock Incentive Plan, as amended
(the "Plan").

     We have reviewed the corporate action of the Company in connection with
this matter and have examined such documents, corporate records and other
instruments as we have deemed necessary for the purpose of this opinion.

     Based upon the foregoing, it is our opinion that the Shares have been duly
authorized and, upon issuance and delivery and payment therefor in accordance
with the provisions of the Plan, will be duly and validly issued, fully paid and
nonassessable.

     We hereby consent to the filing of this opinion with the Securities and
Exchange Commission in connection with the filing of the Registration Statement.

                              Very truly yours,

                              STRADLING YOCCA CARLSON & RAUTH


                              /s/  STRADLING YOCCA CARLSON & RAUTH