S-3/A

As filed with the Securities and Exchange Commission on November 15, 2005.

Registration No. 333-129197

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 1

to

Form S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

CERADYNE, INC.

(Exact name of registrant as specified in its charter)

Delaware	33-0055414
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

3169 Red Hill Avenue

Costa Mesa, California 92626

(714) 549-0421

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Jerrold J. Pellizzon

Vice President and Chief Financial Officer

Ceradyne, Inc.

3169 Red Hill Avenue

Costa Mesa, California 92626

(714) 549-0421

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Robert E. Rich, Esq.

Numan J. Siddiqi, Esq.

Stradling Yocca Carlson & Rauth

660 Newport Center Drive, Suite 1600

Newport Beach, California 92660

(949) 725-4000

Approximate date of commencement of proposed sale to the public: From time to time after this Registration Statement becomes effective.

If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ¨

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  x

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act of 1933, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act of 1933, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box.  ¨

Ceradyne hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until Ceradyne files a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until this registration statement becomes effective on such date as the commission acting pursuant to Section 8(a) may determine.

The information in this prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell, nor does it seek an offer to buy, these securities in any jurisdiction in which the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED NOVEMBER 15, 2005

PROSPECTUS

CERADYNE, INC.

$200,000,000

Common Stock

Debt Securities

Warrants

We may, from time to time in one or more offerings, sell up to $200,000,000 in the aggregate of:

• shares of our common stock;

• our secured or unsecured debt securities, in one or more series, which may be either senior, senior subordinated or subordinated debt securities;

• warrants to purchase shares of our common stock;

• warrants to purchase our debt securities; or

• any combination of the foregoing.

We will provide the specific terms of these securities in supplements to this prospectus. The prospectus supplement may also add, update or change information in this prospectus. You should read this prospectus and any prospectus supplement carefully before you invest. This prospectus may not be used to offer or sell securities unless it includes a prospectus supplement.

Our principal executive offices are located at 3169 Red Hill Avenue, Costa Mesa, California 92626, and our telephone number is (714) 549-0421.

Our common stock is quoted on the Nasdaq National Market under the symbol “CRDN.” On November 14, 2005, the closing sale price as quoted on the Nasdaq National Market was $44.83 per share.

Investing in the securities we may offer involves various risks. See the sections entitled “ Risk Factors” on page 1 and “Note Regarding Forward-Looking Statements” on page 2. Additional risks associated with an investment in our company as well as with the particular types of securities will be described in the related prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is                     , 2005.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS	1
RISK FACTORS	1
NOTE REGARDING FORWARD-LOOKING STATEMENTS	2
WHERE YOU CAN FIND MORE INFORMATION	2
INFORMATION INCORPORATED BY REFERENCE	3
CERADYNE, INC.	4
USE OF PROCEEDS	4
RATIO OF EARNINGS TO FIXED CHARGES	4
GENERAL DESCRIPTION OF SECURITIES	5
DESCRIPTION OF CAPITAL STOCK	5
DESCRIPTION OF DEBT SECURITIES	5
DESCRIPTION OF THE WARRANTS	13
PLAN OF DISTRIBUTION	15
LEGAL MATTERS	17
EXPERTS	17

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf process, we may offer from time to time up to $200,000,000 of the following securities:

• shares of our common stock;

• our secured or unsecured debt securities, in one or more series, which may be either senior, senior subordinated or subordinated debt securities;

• warrants to purchase shares of our common stock;

• warrants to purchase our debt securities; or

• any combination of the foregoing.

This prospectus provides you with a general description of the securities we may offer. Each time we offer securities, we will provide you with a prospectus supplement that describes the specific amounts, prices and terms of the securities we offer. The prospectus supplement also may add, update or change information contained in this prospectus. You should read carefully both this prospectus and any prospectus supplement together with additional information described below under “Information Incorporated By Reference.”

This prospectus does not contain all the information provided in the registration statement we filed with the SEC. For further information about us or the securities offered hereby, you should refer to that registration statement, which you can obtain from the SEC as described below under “Where You Can Find More Information.”

You should rely only on the information contained or incorporated by reference in this prospectus or a prospectus supplement. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus or any prospectus supplement, as well as information we have previously filed with the SEC and incorporated by reference, is accurate as of the date on the front of those documents only. Our business, financial condition, results of operations and prospects may have changed since those dates.

We may sell the securities to or through underwriters, dealers or agents or directly to purchasers. We and our agents reserve the sole right to accept or reject in whole or in part any proposed purchase of securities. The prospectus supplement, which we will provide to you each time we offer securities, will set forth the names of any underwriters, dealers or agents involved in the sale of the securities, and any applicable fee, commission or discount arrangements with them. See “Plan of Distribution.”

RISK FACTORS

Before making an investment decision, you should carefully consider the risks described under “Risk Factors” in the applicable prospectus supplement, together with all of the other information appearing in this prospectus or incorporated by reference into this prospectus and any applicable prospectus supplement, in light of your particular investment objectives and financial circumstances. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The trading price of our securities could decline due to any of these risks, and you may lose all or part of your investment.

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NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, any prospectus supplement, and the documents incorporated by reference herein include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Forward-looking statements are those that predict or describe future events or trends and that do not relate solely to historical matters. You can generally identify forward-looking statements as statements containing the words “believe,” “expect,” “will,” “anticipate,” “intend,” “estimate,” “project,” “plan,” “assume” or other similar expressions, or negatives of those expressions, although not all forward-looking statements contain these identifying words. All statements contained or incorporated by reference in this prospectus and any prospectus supplement regarding our future strategy, future operations, projected financial position, estimated future revenues, projected costs, future prospects, the future of our industries and results that might be obtained by pursuing management’s current plans and objectives are forward-looking statements.

You should not place undue reliance on our forward-looking statements because the matters they describe are subject to known and unknown risks, uncertainties and other unpredictable factors, many of which are beyond our control. Our forward-looking statements are based on the information currently available to us and speak only as of the date on the cover of this prospectus, the date of any prospectus supplement, or, in the case of forward-looking statements incorporated by reference, as of the date of the filing that includes the statement. New risks and uncertainties arise from time to time, and it is impossible for us to predict these matters or how they may affect us. Over time, our actual results, performance or achievements will likely differ from the anticipated results, performance or achievements that are expressed or implied by our forward-looking statements, and such difference might be significant and materially adverse to our security holders. We do not undertake and specifically decline any obligation to update any forward-looking statements or to publicly announce the results of any revisions to any statements to reflect new information or future events or developments.

We have identified some of the important factors that could cause future events to differ from our current expectations and they are described in this prospectus and supplements to this prospectus under the caption “Risk Factors” as well as in our most recent Annual Report on Form 10-K, including without limitation under the captions “Business—Risk Factors,” “Management Discussion and Analysis of Financial Condition and Results of Operations” and “Quantitative and Qualitative Disclosures About Market Risk,” in our most recent Quarterly Report on Form 10-Q, and in other documents that we may file with the SEC, all of which you should review carefully. Please consider our forward-looking statements in light of those risks as you read this prospectus and any prospectus supplement.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, proxy statements and other information with the SEC. You can read our SEC filings over the Internet at the SEC’s website at http://www.sec.gov. You may also read and copy any document we file with the SEC at its public reference facilities at 450 Fifth Street, N.W. Washington, DC 20549. In addition, copies of these reports and other information may be obtained at prescribed rates from the Public Reference Section of the SEC at 450 Fifth Street, N.W., Washington, D.C. 20549. You can get further information about the SEC’s Public Reference Room by calling 1-800-SEC-0330.

We have filed with the SEC a registration statement on Form S-3 under the Securities Act. This prospectus does not contain all the information in the registration statement. We have omitted parts of the registration statement, as permitted by the rules and regulations of the SEC. You may inspect and copy the registration statement, as amended, including exhibits, at the SEC’s public reference facilities or website. If we have filed any contract or other document as an exhibit to the registration statement or any other document incorporated by reference in the registration statement, you should read the exhibit for a more complete understanding of the document or matter involved. Each statement regarding a contract or other document is qualified in its entirety by reference to the actual document.

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INFORMATION INCORPORATED BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it. This means that we can disclose important information to you by referring you to those documents. The information we incorporate by reference is considered a part of this prospectus, and later information we file with the SEC will automatically update and supersede this information. The following documents filed with the SEC (in each case, File No. 000-13059) are incorporated by reference in this prospectus:

• our Annual Report on Form 10-K for the year ended December 31, 2004;

• our Quarterly Report on Form 10-Q for the quarter ended March 31, 2005;

• our Quarterly Report on Form 10-Q for the quarter ended June 30, 2005;

• our Quarterly Report on Form 10-Q for the quarter ended September 30, 2005;

• our Current Report on Form 8-K, filed with the SEC on August 26, 2004 (but excluding information “furnished” under Items 7.01 and 9.01), as amended by Amendment No. 1 thereto (with respect to the consolidated financial statements of ESK Ceramics GmbH & Co. KG for the years ended December 31, 2001, 2002 and 2003 included in Item 9.01), filed with the SEC on November 8, 2004, as further amended by Amendment No. 2 thereto, filed with the SEC on October 21, 2005;

• our Current Report on Form 8-K (dated February 28, 2005) filed with the SEC on March 4, 2005;

• our Current Report on Form 8-K, filed with the SEC on May 26, 2005;

• our definitive Proxy Statement dated April 18, 2005, filed in connection with our 2005 Annual Meeting of Stockholders; and

• the description of our common stock contained in our registration statement on Form 8-B filed under the Exchange Act on June 8, 1987, including any amendment or report hereafter filed for the purpose of updating such description.

We are also incorporating by reference any future filings we make with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act until this offering is completed.

You may obtain any of the documents incorporated by reference through the SEC or the SEC’s website as described above. You may also obtain copies of these documents, other than exhibits to such documents, free of charge upon written or oral request to Jerrold J. Pellizzon, 3169 Red Hill Avenue, Costa Mesa, California 92626, telephone: (714) 549-0421.

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CERADYNE, INC.

We develop, manufacture and market advanced technical ceramic products, ceramics powders and components for defense, industrial, automotive/diesel and commercial applications. Our competitive advantage results from our expertise in ceramic material science as well as our vertically integrated approach of designing much of our key equipment and controlling the manufacturing process from raw material powders to finished product. This allows us to design and manufacture precision, high quality advanced technical ceramic products to meet demanding customer specifications. Our customers include the U.S. government, prime government contractors and large industrial and commercial manufacturers in both domestic and international markets.

Our principal executive offices are located at 3169 Red Hill Avenue, Costa Mesa, California 92626, and our telephone number is (714) 549-0421. We maintain a website at www.ceradyne.com. The reference to our website address does not constitute incorporation by reference into this prospectus of the information contained at that site. We are organized as a Delaware corporation.

USE OF PROCEEDS

We will retain broad discretion over the use of the net proceeds from the sale of our securities offered hereby. Except as described in any prospectus supplement, we currently intend to use the net proceeds from the sale of securities offered by this prospectus to repay or refinance debt, and for working capital, capital expenditures and other general corporate purposes. We may also use the proceeds to fund acquisitions of businesses, technologies or product lines that complement our current business. However, we currently have no commitments or agreements for any specific acquisitions. Pending application of the net proceeds, we intend to invest the net proceeds of the offering in investment-grade, interest-bearing securities.

RATIO OF EARNINGS TO FIXED CHARGES

The following table sets forth our ratio of earnings to fixed charges for the periods indicated:

	Year Ended December 31,					Nine Months Ended September 30, 2005
	2000	2001	2002	2003	2004
Ratio of earnings to fixed charges	20.7	17.7	9.8	46.3	19.8	9.1

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GENERAL DESCRIPTION OF SECURITIES

We, directly or through agents, dealers or underwriters designated from time to time, may offer, issue and sell, together or separately, in one or more offerings, up to $200,000,000 in the aggregate of:

• shares of our common stock, par value $0.01 per share;

• our secured or unsecured debt securities, in one or more series, which may be either senior, senior subordinated or subordinated debt securities;

• warrants to purchase common stock or debt securities; or

• any combination of the foregoing, either individually or as units consisting of one or more of the foregoing, each on terms to be determined at the time of sale.

We may issue the debt securities as exchangeable for and/or convertible into shares of our common stock. The common stock, the debt securities, and the warrants are collectively referred to herein as the securities. This prospectus provides you with a general description of the securities we may offer. Each time we offer securities, we will provide you with a prospectus supplement that describes the specific amounts, prices and terms of the securities we offer. The securities involve various risks that we will describe in the section entitled “Risk Factors” that will be included in each prospectus supplement.

DESCRIPTION OF CAPITAL STOCK

We have authority under our restated certificate of incorporation, as amended, to issue up to 40,000,000 shares of common stock, par value $0.01 per share. As of November 14, 2005, there were 24,658,350 shares of our common stock outstanding.

Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders, except in the election of directors stockholders are entitled to cumulate their votes if timely notice is given as provided in our restated certificate incorporation, as amended. Holders of common stock are entitled to receive ratably such dividends, if any, as may be declared by our board of directors out of legally available funds. Upon the liquidation, dissolution or winding up of Ceradyne, the holders of common stock are entitled to receive ratably our assets available after the payment of all debts and other liabilities. Holders of common stock have no preemptive, subscription, redemption or conversion rights.

DESCRIPTION OF DEBT SECURITIES

This prospectus describes certain general terms and provisions of our debt securities. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. The following description of debt securities will apply to the debt securities offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of debt securities may specify different or additional terms.

We may offer under this prospectus up to $200,000,000 aggregate principal amount of secured or unsecured debt securities, or if debt securities are issued at a discount, or in a foreign currency or composite currency, such principal amount as may be sold for an initial public offering price of up to $200,000,000. The debt securities may be either senior debt securities, senior subordinated debt securities or subordinated debt securities.

The debt securities offered hereby will be issued under an indenture between us and a trustee. We have filed a copy of the form indenture as an exhibit to the registration statement and you should read the indenture for provisions that may be important to you. We have summarized select portions of the indenture below. The summary is not complete.

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General

The terms of each series of debt securities will be established by or pursuant to a resolution of our Board of Directors and detailed or determined in the manner provided in a Board of Directors’ resolution, an officers’ certificate or by a supplemental indenture. The particular terms of each series of debt securities will be described in a prospectus supplement relating to the series, including any pricing supplement.

We can issue an unlimited amount of debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium or at a discount. We will set forth in a prospectus supplement (including any pricing supplement) relating to any series of debt securities being offered, the initial offering price, the aggregate principal amount and the following terms of the debt securities:

• the title of the debt securities;

• the price or prices (expressed as a percentage of the aggregate principal amount) at which we will sell the debt securities;

• any limit on the aggregate principal amount of the debt securities;

• the date or dates on which we will pay the principal on the debt securities;

• the rate or rates (which may be fixed or variable) per annum or the method used to determine the rate or rates (including any commodity, commodity index, stock exchange index or financial index) at which the debt securities will bear interest, the date or dates from which interest will accrue, the date or dates on which interest will commence and be payable and any regular record date for the interest payable on any interest payment date;

• the place or places where the principal of, premium, and interest on the debt securities will be payable;

• the terms and conditions upon which we may redeem the debt securities;

• any obligation we have to redeem or purchase the debt securities pursuant to any sinking fund or analogous provisions or at the option of a holder of debt securities;

• the dates on which and the price or prices at which we will repurchase the debt securities at the option of the holders of debt securities and other detailed terms and provisions of these repurchase obligations;

• the denominations in which the debt securities will be issued, if other than denominations of $1,000 and any integral multiple thereof;

• whether the debt securities will be issued in the form of certificated debt securities or global debt securities;

• the portion of principal amount of the debt securities payable upon declaration of acceleration of the maturity date, if other than the principal amount;

• the currency of denomination of the debt securities;

• the designation of the currency, currencies or currency units in which payment of principal of, premium and interest on the debt securities will be made;

• if payments of principal of, premium or interest on the debt securities will be made in one or more currencies or currency units other than that or those in which the debt securities are denominated, the manner in which the exchange rate with respect to these payments will be determined;

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• the manner in which the amounts of payment of principal of, premium or interest on the debt securities will be determined, if these amounts may be determined by reference to an index based on a currency or currencies other than that in which the debt securities are denominated or designated to be payable or by reference to a commodity, commodity index, stock exchange index or financial index;

• any provisions relating to any security provided for the debt securities;

• any addition to or change in the events of default described in this prospectus or in the indenture with respect to the debt securities and any change in the acceleration provisions described in this prospectus or in the indenture with respect to the debt securities;

• any addition to or change in the covenants described in this prospectus or in the indenture with respect to the debt securities;

• any other terms of the debt securities, which may modify or delete any provision of the indenture as it applies to that series; and

• any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents with respect to the debt securities.

We may issue debt securities that are exchangeable and/or convertible into shares of our common stock. The terms, if any, on which the debt securities may be exchanged for and/or converted will be set forth in the applicable prospectus supplement. Such terms may include provisions for conversion, either mandatory, at the option of the holder or at our option, in which case the number of shares of common stock or other securities to be received by the holders of debt securities would be calculated as of a time and in the manner stated in the prospectus supplement.

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Payment of Interest and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company, as Depositary, or a nominee of the Depositary (we will refer to any debt security represented by a global debt security as a book-entry debt security), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a certificated debt security), as described in the applicable prospectus supplement. Except as described under “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at the trustee’s office or paying agencies in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

You may transfer certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the old certificate representing those certificated debt securities

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and either we or the trustee will reissue the old certificate to the new holder or we or the trustee will issue a new certificate to the new holder.

Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the Depositary, and registered in the name of the Depositary or a nominee of the Depositary.

The Depositary has indicated it intends to follow the following procedures with respect to book-entry debt securities.

Ownership of beneficial interests in book-entry debt securities will be limited to persons that have accounts with the Depositary for the related global debt security, whom we refer to as participants, or persons that may hold interests through participants. Upon the issuance of a global debt security, the Depositary will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal amounts of the book-entry debt securities represented by the global debt security beneficially owned by such participants. The accounts to be credited will be designated by any dealers, underwriters or agents participating in the distribution of the book-entry debt securities. Ownership of book-entry debt securities will be shown on, and the transfer of the ownership interests will be effected only through, records maintained by the Depositary for the related global debt security (with respect to interests of participants) and on the records of participants (with respect to interests of persons holding through participants). The laws of some states may require that certain purchasers of securities take physical delivery of such securities in definitive form. These laws may impair the ability to own, transfer or pledge beneficial interests in book-entry debt securities.

So long as the Depositary for a global debt security, or its nominee, is the registered owner of that global debt security, the Depositary or its nominee, as the case may be, will be considered the sole owner or holder of the book-entry debt securities represented by such global debt security for all purposes under the indenture. Except as described herein, beneficial owners of book-entry debt securities will not be entitled to have securities registered in their names, will not receive or be entitled to receive physical delivery of a certificate in definitive form representing securities and will not be considered the owners or holders of those securities under the indenture. Accordingly, to exercise any rights of a holder under the indenture, each person beneficially owning book-entry debt securities must rely on the procedures of the Depositary for the related global debt security and, if that person is not a participant, on the procedures of the participant through which that person owns its interest.

We understand, however, that under existing industry practice, the Depositary will authorize the persons on whose behalf it holds a global debt security to exercise certain rights of holders of debt securities, and the indenture provides that we, the trustee and our respective agents will treat as the holder of a debt security the persons specified in a written statement of the Depositary with respect to that global debt security for purposes of obtaining any consents or directions required to be given by holders of the debt securities pursuant to the indenture.

We will make payments of principal of, and premium and interest on book-entry debt securities to the Depositary or its nominee, as the case may be, as the registered holder of the related global debt security. We, the trustee and any other agent of ours or agent of the trustee will not have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests.

We expect that the Depositary, upon receipt of any payment of principal of, premium or interest on a global debt security, will immediately credit participants’ accounts with payments in amounts proportionate to the respective amounts of book-entry debt securities held by each participant as shown on the records of the Depositary. We also expect that payments by participants to owners of beneficial interests in book-entry debt securities held through those participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of those participants.

We will issue certificated debt securities in exchange for each global debt security if the Depositary is at any time unwilling or unable to continue as Depositary or ceases to be a clearing agency registered under the Exchange Act, and a successor Depositary registered as a clearing agency under the Exchange Act is not appointed

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by us within 90 days. In addition, we may at any time and in our sole discretion determine not to have any of the book-entry debt securities of any series represented by one or more global debt securities and, in that event, we will issue certificated debt securities in exchange for the global debt securities of that series. Global debt securities will also be exchangeable by the holders for certificated debt securities if an event of default with respect to the book-entry debt securities represented by those global debt securities has occurred and is continuing. Any certificated debt securities issued in exchange for a global debt security will be registered in such name or names as the Depositary shall instruct the trustee. We expect that such instructions will be based upon directions received by the Depositary from participants with respect to ownership of book-entry debt securities relating to such global debt security.

We have obtained the foregoing information in this section concerning the Depositary and the Depositary’s book-entry system from sources we believe to be reliable. We take no responsibility for the Depositary’s performance of its obligations under the rules and regulations governing its operations.

No Protection in the Event of a Change in Control

Unless we provide otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions which may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control).

Covenants

Unless we provide otherwise in the applicable prospectus supplement, the debt securities will not contain any restrictive covenants, including covenants restricting us or any of our subsidiaries from incurring, issuing, assuming or guarantying any indebtedness secured by a lien on any of our or our subsidiaries’ property or capital stock, or restricting us or any of our subsidiaries from entering into any sale and leaseback transactions.

Consolidation, Merger and Sale of Assets

Unless we provide otherwise in the applicable prospectus supplement, we may not consolidate with or merge into, or convey, transfer or lease all or substantially all of our properties and assets to, any person (a “successor person”), and we may not permit any person to merge into, or convey, transfer or lease its properties and assets substantially as an entirety to us, unless:

• the successor person is a corporation, partnership, trust or other entity organized and validly existing under the laws of any U.S. domestic jurisdiction and expressly assumes our obligations on the debt securities and under the indenture;

• immediately after giving effect to the transaction, no event of default, and no event which, after notice or lapse of time, or both, would become an event of default, shall have occurred and be continuing under the indenture; and

• certain other conditions are met.

Events of Default

Unless we provide otherwise in the applicable prospectus supplement, “event of default” means with respect to any series of debt securities, any of the following:

• default in the payment of any interest upon any debt security of that series when it becomes due and payable, and continuance of that default for a period of 30 days (unless the entire amount of such payment is deposited by us with the trustee or with a paying agent prior to the expiration of the 30-day period);

• default in the payment of principal of or premium on any debt security of that series when due and payable;

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• default in the deposit of any sinking fund payment, when and as due in respect of any debt security of that series;

• default in the performance or breach of any other covenant or warranty by us in the indenture (other than a covenant or warranty that has been included in the indenture solely for the benefit of a series of debt securities other than that series), which default continues uncured for a period of 60 days after we receive written notice from the trustee or we and the trustee receive written notice from the holders of at least 25% in principal amount of the outstanding debt securities of that series as provided in the indenture;

• certain events of our bankruptcy, insolvency or reorganization; and

• any other event of default provided with respect to debt securities of that series that is described in the applicable prospectus supplement accompanying this prospectus.

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. An event of default may also be an event of default under our bank credit agreements or other debt securities in existence from time to time and under certain guaranties by us of any subsidiary indebtedness. In addition, certain events of default or an acceleration under the indenture may also be an event of default under some of our other indebtedness outstanding from time to time.

Unless we provide otherwise in the applicable prospectus supplement, if an event of default with respect to debt securities of any series at the time outstanding occurs and is continuing (other than certain events of our bankruptcy, insolvency or reorganization), then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by written notice to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of and accrued and unpaid interest, if any, of all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, of all outstanding debt securities will become and be immediately due and payable without any declaration or other act by the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before the trustee has obtained a judgment or decree for payment of the money due, the holders of a majority in principal amount of the outstanding debt securities of that series may, subject to our having paid or deposited with the trustee a sum sufficient to pay overdue interest and principal which has become due other than by acceleration and certain other conditions, rescind and annul such acceleration if all events of default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. For information as to waiver of defaults see the discussion under “Modification and Waiver” below. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of the discount securities upon the occurrence of an event of default and the continuation of an event of default.

Unless we provide otherwise in the applicable prospectus supplement, the indenture will provide that the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any holder of outstanding debt securities, unless the trustee receives indemnity satisfactory to it against any loss, liability or expense. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series shall have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

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Unless we provide otherwise in the applicable prospectus supplement, no holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

• that holder has previously given to the trustee written notice of a continuing event of default with respect to debt securities of that series; and

• the holders of at least 25% in principal amount of the outstanding debt securities of that series have made written request, and offered reasonable indemnity, to the trustee to institute such proceeding as trustee, and the trustee shall not have received from the holders of a majority in principal amount of the outstanding debt securities of that series a direction inconsistent with that request and has failed to institute the proceeding within 60 days.

Notwithstanding the foregoing, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, premium and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment.

The indenture requires us, within 90 days after the end of our fiscal year, to furnish to the trustee a certificate as to compliance with the indenture. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if it in good faith determines that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

Unless we provide otherwise in the applicable prospectus supplement, we and the trustee may modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We and the trustee may not make any modification or amendment without the consent of the holder of each affected debt security then outstanding if that amendment will:

• change the amount of debt securities whose holders must consent to an amendment or waiver;

• reduce the rate of or extend the time for payment of interest (including default interest) on any debt security;

• reduce the principal of or premium on or change the fixed maturity of any debt security or reduce the amount of, or postpone the date fixed for, the payment of any sinking fund or analogous obligation with respect to any series of debt securities;

• reduce the principal amount of discount securities payable upon acceleration of maturity;

• waive a default in the payment of the principal of, premium or interest on any debt security (except a rescission of acceleration of the debt securities of any series by the holders of at least a majority in aggregate principal amount of the then outstanding debt securities of that series and a waiver of the payment default that resulted from that acceleration);

• make the principal of or premium or interest on any debt security payable in currency other than that stated in the debt security;

• make any change to certain provisions of the indenture relating to, among other things, the right of holders of debt securities to receive payment of the principal of, premium and interest on those debt securities, the right of holders to institute suit for the enforcement of any payment or the right of holders to waive past defaults or to amend the limitations described in this bullet point; or

• waive a redemption payment with respect to any debt security or change any of the provisions with respect to the redemption of any debt securities.

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Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may, on behalf of the holders of all debt securities of that series, waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may, on behalf of the holders of all the debt securities of that series, waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series; PROVIDED, HOWEVER, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless the terms of the applicable series of debt securities provide otherwise, we may be discharged from any and all obligations in respect of the debt securities of any series (except for certain obligations to register the transfer or exchange of debt securities of the series, to replace stolen, lost or mutilated debt securities of the series, and to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, foreign government obligations (as described at the end of this section), that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants to pay and discharge each installment of principal, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of such payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an officers’ certificate and an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable United States federal income tax law, in either case to the effect that holders of the debt securities of such series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amount and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants. The indenture provides that, unless the terms of the applicable series of debt securities provide otherwise, upon compliance with certain conditions, we may omit to comply with the restrictive covenants contained in the indenture, as well as any additional covenants contained in a supplement to the indenture, a board resolution or an officers’ certificate delivered pursuant to the indenture. The conditions include:

• depositing with the trustee money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, foreign government obligations, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants to pay principal, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities; and

• delivering to the trustee an opinion of counsel to the effect that the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit and related covenant defeasance and will be subject to United States federal income tax in the same amount and in the same manner and at the same times as would have been the case if the deposit and related covenant defeasance had not occurred.

Covenant Defeasance and Events of Default. In the event we exercise our option, as described above, not to comply with certain covenants of the indenture with respect to any series of debt securities and the debt securities of that series are declared due and payable because of the occurrence of any event of default, the amount of money and/or U.S. government obligations or foreign government obligations on deposit with the trustee will be sufficient

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to pay amounts due on the debt securities of that series at the time of their stated maturity but may not be sufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. However, we will remain liable for those payments.

“Foreign government obligations” means, with respect to debt securities of any series that are denominated in a currency other than U.S. dollars:

• direct obligations of the government that issued or caused to be issued such currency for the payment of which obligations its full faith and credit is pledged, which are not callable or redeemable at the option of the issuer thereof; or

• obligations of a person controlled or supervised by or acting as an agency or instrumentality of that government the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by that government, which are not callable or redeemable at the option of the issuer thereof.

DESCRIPTION OF THE WARRANTS

We may issue debt warrants to purchase debt securities, as well as equity warrants to purchase common stock. The warrants may be issued independently or together with any securities and may be attached to or separate from the securities. The warrants are to be issued under warrant agreements to be entered into between us and a bank or trust company, as warrant agent, all as shall be set forth in the prospectus supplement relating to warrants being offered pursuant to such prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

Debt Warrants

The applicable prospectus supplement will describe the terms of debt warrants offered, the warrant agreement relating to the debt warrants and the debt warrant certificates representing the debt warrants, including the following:

• the title of the debt warrants;

• the aggregate number of the debt warrants;

• the price or prices at which the debt warrants will be issued;

• the provisions, if any, for changes to or adjustments in the exercise price;

• the designation, aggregate principal amount and terms of the debt securities purchasable upon exercise of the debt warrants, and the procedures and conditions relating to the exercise of the debt warrants;

• the designation and terms of any related debt securities with which the debt warrants are issued, and the number of the debt warrants issued with each debt security;

• the date, if any, on and after which the debt warrants and the related debt securities will be separately transferable;

• the principal amount of debt securities purchasable upon exercise of each debt warrant;

• the date on which the right to exercise the debt warrants will commence, and the date on which this right will expire;

• the maximum or minimum number of debt warrants which may be exercised at any time;

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• a discussion of any material federal income tax consequences of holding or exercising the debt warrants; and

• any other terms of the debt warrants and terms, procedures and limitations relating to the exercise of debt warrants.

Debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations, and debt warrants may be exercised at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement. Prior to the exercise of their debt warrants, holders of debt warrants will not have any of the rights of holders of the debt securities purchasable upon exercise and will not be entitled to payment of principal of or any premium, if any, or interest on the debt securities purchasable upon exercise.

Equity Warrants

The applicable prospectus supplement will describe the following terms of equity warrants offered:

• the title of the equity warrants;

• the securities (i.e., common stock) for which the equity warrants are exercisable;

• the price or prices at which the equity warrants will be issued;

• the provisions, if any, for changes to or adjustments in the exercise price;

• the date on which the right to exercise the equity warrant shall commence and the date on which the right will expire;

• if applicable, the number of equity warrants issued with each share of common stock;

• if applicable, the date on and after which the equity warrants and the related common stock will be separately transferable;

• a discussion of any material federal income tax consequences of holding or exercising the equity warrants; and

• any other terms of the equity warrants, including terms, procedures and limitations relating to the exchange and exercise of equity warrants.

Holders of equity warrants will not be entitled, by virtue of being such holders, to vote, consent, receive dividends, receive notice as stockholders with respect to any meeting of stockholders for the election of our directors or any other matter, or to exercise any rights whatsoever as our stockholders.

The exercise price payable and the number of shares of common stock purchasable upon the exercise of each equity warrant will be subject to adjustment in certain events, including the issuance of a stock dividend to holders of common stock or a stock split, reverse stock split, combination, subdivision or reclassification of common stock. In lieu of adjusting the number of shares of common stock purchasable upon exercise of each equity warrant, we may elect to adjust the number of equity warrants. We may, at our option, reduce the exercise price at any time. No fractional shares will be issued upon exercise of equity warrants, but we will pay the cash value of any fractional shares otherwise issuable. Notwithstanding the foregoing, in case of any consolidation, merger, or sale or conveyance of our property as an entirety or substantially as an entirety, the holder of each outstanding equity warrant shall have the right to the kind and amount of shares of stock and other securities and property, including cash, receivable by a holder of the number of shares of common stock into which the equity warrant was exercisable immediately prior to such transaction.

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Exercise of Warrants

Each warrant will entitle the holder to purchase for cash such principal amount of securities or shares of stock at such exercise price as shall in each case be set forth in, or be determinable as set forth in, the prospectus supplement relating to the warrants offered thereby. Warrants may be exercised at any time up to the close of business on the expiration date set forth in the prospectus supplement relating to the warrants offered thereby. After the close of business on the expiration date, unexercised warrants will become void.

The warrants may be exercised as set forth in the prospectus supplement relating to the warrants offered. Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the securities purchasable upon such exercise. If less than all of the warrants represented by such warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants.

PLAN OF DISTRIBUTION

We may sell the securities through underwriters or dealers, through agents, or directly to one or more purchasers or through a combination of these methods. The applicable prospectus supplement will describe the terms of the offering of the securities, including:

• the name or names of any underwriters, if any, and if required, any dealers or agents;

• the purchase price of the securities and the proceeds we will receive from the sale;

• any underwriting discounts and other items constituting underwriters’ compensation;

• any initial public offering price;

• any discounts or concessions allowed or reallowed or paid to dealers; and

• any securities exchange or market on which the securities may be listed.

We may distribute the securities from time to time in one or more transactions at:

• a fixed price or prices, which may be changed;

• market prices prevailing at the time of sale;

• prices related to such prevailing market prices; or

• negotiated prices.

Only underwriters named in the prospectus supplement are underwriters of the securities offered by the prospectus supplement.

If we use underwriters in the sale, they will acquire the securities for their own account and may resell them from time to time in one or more transactions at a fixed public offering price or at varying prices determined at the time of sale. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to specific limited conditions, the underwriters will be obligated to purchase all the securities of the series offered by the prospectus supplement. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time.

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If we use a dealer in the sale of the securities being offered pursuant to this prospectus, we will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale.

We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities and we will describe any commissions we will pay the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, our agent will act on a best-efforts basis for the period of its appointment.

We may authorize agents or underwriters to solicit offers by institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

In connection with the sale of the securities, underwriters, dealers or agents may receive compensation from us or from purchasers of the securities for whom they act as agents in the form of discounts, concessions or commissions. Underwriters may sell the securities to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters or commissions from the purchasers for whom they may act as agents. Underwriters, dealers and agents that participate in the distribution of the securities, and any institutional investors or others that purchase securities directly and then resell the securities, may be deemed to be underwriters, and any discounts or commissions received by them from us and any profit on the resale of the securities by them may be deemed to be underwriting discounts and commissions under the Securities Act.

We may provide agents and underwriters with indemnification against particular civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents or underwriters may make with respect to such liabilities. Agents and underwriters may engage in transactions with, or perform services for, us in the ordinary course of business.

In addition, we may enter into derivative transactions with third parties (including the writing of options), or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with such a transaction the third parties may, pursuant to this prospectus and the applicable prospectus supplement, sell securities covered by this prospectus and the applicable prospectus supplement. If so, the third party may use securities borrowed from us or others to settle such sales and may use securities received from us to close out any related short positions, provided that such short positions were not entered into prior to the date that the registration statement, of which this prospectus is a part, was declared effective by the SEC. We may also loan or pledge securities covered by this prospectus and the applicable prospectus supplement to third parties, who may sell the loaned securities or, in an event of default in the case of a pledge, sell the pledged securities pursuant to this prospectus and the applicable prospectus supplement. The third party in such sale transactions will be an underwriter and will be identified in the applicable prospectus supplement or in a post-effective amendment.

All securities we offer other than common stock will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Underwriters may engage in stabilizing and syndicate covering transactions in accordance with Rule 104 under the Exchange Act. Rule 104 permits stabilizing bids to purchase the securities being offered as long as the stabilizing bids do not exceed a specified maximum. Underwriters may over-allot the offered securities in connection with the offering, thus creating a short position in their account. Syndicate covering transactions involve purchases of the offered securities by underwriters in the open market after the distribution has been completed in order to cover syndicate short positions. Underwriters may also cover an over-allotment or short position by exercising their over-allotment option, if any. Stabilizing and syndicate covering transactions may cause the price of the offered securities to be higher than it would otherwise be in the absence of these transactions. These transactions, if commenced, may be discontinued at any time.

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LEGAL MATTERS

Stradling Yocca Carlson & Rauth, a Professional Corporation, 660 Newport Center Drive, Suite 1600, Newport Beach, California, will provide us with an opinion as to the legality of the securities we are offering.

EXPERTS

The consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) of Ceradyne, Inc. incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2004 have been so incorporated in reliance on the report (which contains an explanatory paragraph relating to the exclusion by management of ESK Ceramics and its subsidiaries from its assessment of internal controls over financial reporting as of December 31, 2004 because they were acquired by Ceradyne in a purchase business combination during 2004) of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

The consolidated financial statements of ESK Ceramics GmbH & Co. KG for the years ended December 31, 2001, 2002 and 2003, incorporated in this prospectus by reference to our Current Report on Form 8-K, filed with the SEC on August 26, 2004, as amended by Amendment No. 1 thereto, filed with the SEC on November 8, 2004, have been so incorporated in reliance on the report of KPMG Deutsche Treuhand-Gesellschaft Aktiengesellschaft Wirtschaftsprüfungsgesellschaft, independent public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The following table sets forth the costs and expenses, other than underwriting discounts, payable by the registrant in connection with the offering of the securities being registered. All the amounts shown are estimates except for the SEC registration fee.

SEC registration fee	$	23,540
Printing fees and expenses		320,000
Transfer Agent fees		3,500
Trustee/issuing and paying agent fees and expenses		10,000
Legal fees and expenses		250,000
Accounting fees and expenses		60,000
Miscellaneous expenses		12,960
Total		$680,000

Item 15. Indemnification of Directors and Officers

We are a Delaware corporation. Subsection (b)(7) of Section 102 of the Delaware General Corporation Law, or the DGCL, enables a corporation in its original certificate of incorporation or an amendment thereto to eliminate or limit the personal liability of a director to the corporation or its stockholders for monetary damages for breach of the director’s fiduciary duty, except (i) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) pursuant to Section 174 of the DGCL (providing for liability of directors for unlawful payment of dividends or unlawful stock purchases or redemptions) or (iv) for any transaction from which the director derived an improper personal benefit.

Subsection (a) of Section 145 of the DGCL empowers a corporation to indemnify any present or former director, officer, employee or agent of the corporation, or any individual who served or is serving at the corporation’s request as a director, officer, employee or agent of another organization, who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation), against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding provided that such director, officer, employee or agent acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, the best interests of the corporation, and, with respect to any criminal action or proceeding, provided further that such director, officer, employee or agent had no reasonable cause to believe his or her conduct was unlawful.

Subsection (b) of Section 145 of the DGCL empowers a corporation to indemnify any present or former director, officer, employee or agent or the corporation, or any individual who served or is serving at the corporation’s request as a director, officer, employee or agent of another corporation, who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor by reason of the fact that such person acted in any of the capacities set forth above, against expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit provided that such director, officer, employee or agent acted in good faith and in a manner he or she reasonably believed to be in, or not opposed to, the best interests of the corporation, except that no indemnification may be made in respect of any claim, issue or matter as to which such director, officer, employee or agent shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or the court in which such action or suit was brought shall determine upon application that, despite the adjudication of liability but in view of all of the circumstances of the case, such director

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or officer is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery or such other court shall deem proper.

Section 145 of the DGCL further provides that (i) to the extent a present or former director or officer has been successful on the merits or otherwise in the defense of any action, suit or proceeding referred to in subsections (a) and (b) of Section 145 of the DGCL, or in the defense of any claim, issue or matter therein, he or she shall be indemnified against expenses (including attorneys’ fees) actually and reasonably incurred by him or her in connection therewith; (ii) the indemnification and advancement of expenses provided for, by, or granted pursuant to, Section 145 of the DGCL shall not be deemed exclusive of any other rights to which the persons seeking indemnification may be entitled; and (iii) the corporation is empowered to purchase and maintain insurance on behalf of a present or former director, officer, employee or agent of the corporation, or any individual who is or was serving at the corporation’s request as a director, officer or employee of another organization, against any liability asserted against him or her or incurred by him or her in any such capacity, or arising out of his or her status as such, whether or not the corporation would have the power to indemnify him or her against such liabilities under Section 145 of the DGCL.

Our restated certificate of incorporation, as amended, provides that our directors shall not be personally liable to us or our stockholders for monetary damages for breach of fiduciary duty as a director, to the fullest extent permitted by the DGCL. Our bylaws, as amended, provide for indemnification of officers and directors to the fullest extent and in the manner permitted by the DGCL. Section 145 of the DGCL makes provision for such indemnification in terms sufficiently broad to cover officers and directors under certain circumstances for liabilities arising under the Securities Act.

We have entered into indemnification agreements with substantially all of our executive officers and directors which provide indemnification under certain circumstances for acts and omissions which may not be covered by any directors’ and officers’ liability insurance.

Item 16. Exhibits

Exhibit Number	Description
1.1*	Form of Underwriting Agreement
4.1**	Form of Indenture
4.2*	Form of Debt Security
4.3*	Form of Warrant Agreement, if any, including form of Warrant
5.1	Opinion of Stradling Yocca Carlson & Rauth, a Professional Corporation
12.1	Computation of Ratio of Earnings to Fixed Charges
23.1	Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm
23.2	Consent of KPMG Deutsche Treuhand-Gesellschaft Aktiengesellschaft Wirthschaftsprüfungsgesellschaft.
23.3	Consent of Stradling Yocca Carlson & Rauth, a Professional Corporation (included in its opinion filed as Exhibit 5.1 hereto)
24.1**	Power of Attorney
25.1*	Form T-1 Statement of Eligibility of Trustee

* To be filed by amendment or as an exhibit to a Current Report on Form 8-K under the Exchange Act, subsequent to effectiveness, if necessary.

** Previously filed.

Item 17. Undertakings

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

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(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Securities and Exchange Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Securities and Exchange Commission by the registrant pursuant to Section 13 or 15(d) of the Securities Exchange Act that are incorporated by reference in the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

(d) The undersigned registrant hereby undertakes that:

(1) For purposes of determining any liability under the Securities Act, the information omitted from the form of prospectus filed as part of this registration statement in reliance upon Rule 430A and contained in a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed to be part of this registration statement as of the time it was declared effective.

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(2) For the purpose of determining any liability under the Securities Act, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(e) The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act (the “Act”) in accordance with the rules and regulations prescribed by the Securities and Exchange Commission under Section 305(b)(2) of the Act.

II-4

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all the requirements for filing on Form S-3 and has duly caused this Amendment No. 1 to the registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Costa Mesa, State of California, on November 15, 2005.

CERADYNE, INC.
By:	/s/    JERROLD J. PELLIZZON
	Jerrold J. Pellizzon
	Vice President,
	Chief Financial Officer and Secretary

Pursuant to the requirements of the Securities Act of 1933, as amended, this Amendment No. 1 to the registration statement has been signed by the following persons in the capacities indicated on November 15, 2005.

Signature	Title
*         Joel P. Moskowitz	Chairman of the Board, Chief Executive Officer and President (Principal Executive Officer)
/s/    JERROLD J. PELLIZZON         Jerrold J. Pellizzon	Vice President, Chief Financial Officer and Secretary (Principal Financial and Accounting Officer)
*         Richard A. Alliegro	Director
*         Eduard Bagdasarian	Director

II-5

	Signature	Title
	*         Frank Edelstein	Director
	*         Richard A. Kertson	Director
	*         Milton L. Lohr	Director
*By:	/S/    JERROLD J. PELLIZZON
	Jerrold J. Pellizzon As Attorney-in-Fact

II-6

EXHIBIT INDEX

Exhibit Number	Description
1.1*	Form of Underwriting Agreement
4.1**	Form of Indenture
4.2*	Form of Debt Security
4.3*	Form of Warrant Agreement, if any, including form of Warrant
5.1	Opinion of Stradling Yocca Carlson & Rauth, a Professional Corporation
12.1	Computation of Ratio of Earnings to Fixed Charges
23.1	Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm
23.2	Consent of KPMG Deutsche Treuhand-Gesellschaft Aktiengesellschaft Wirthschaftsprüfungsgesellschaft.
23.3	Consent of Stradling Yocca Carlson & Rauth, a Professional Corporation (included in its opinion filed as Exhibit 5.1 hereto)
24.1**	Power of Attorney
25.1*	Form T-1 Statement of Eligibility of Trustee

* To be filed by amendment or as an exhibit to a Current Report on Form 8-K under the Exchange Act, subsequent to effectiveness, if necessary.

** Previously filed.

EX-5.1

Exhibit 5.1

STRADLING YOCCA CARLSON & RAUTH
A PROFESSIONAL CORPORATION ATTORNEYS AT LAW 660 NEWPORT CENTER DRIVE, SUITE 1600 NEWPORT BEACH, CA 92660-6422 TELEPHONE (949) 725-4000 FACSIMILE (949) 725-4100	SAN FRANCISCO OFFICE 44 MONTGOMERY STREET, SUITE 4200 SAN FRANCISCO, CALIFORNIA 94104 TELEPHONE (415) 283-2240 FACSIMILE   (415) 283-2255
	SANTA BARBARA OFFICE 302 OLIVE STREET SANTA BARBARA, CALIFORNIA 93101 TELEPHONE (805) 564-0065 FACSIMILE   (805) 564-1044

November 15, 2005

Ceradyne, Inc.

3169 Redhill Avenue

Costa Mesa, California 92626

Re: Ceradyne, Inc., Registration Statement on Form S-3; $200,000,000 Aggregate Offering Price of Securities

Ladies and Gentlemen:

In connection with the registration statement on Form S-3 (Registration File No. 333-129197, the “Registration Statement”) filed by Ceradyne, Inc., a Delaware corporation (the “Company”), with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), you have requested our opinion with respect to the matters set forth below.

You have provided us with a draft of the Registration Statement in the form in which it was filed, which includes the prospectus (the “Prospectus”). The Prospectus provides that it will be supplemented in the future by one or more supplements to the Prospectus (each, a “Prospectus Supplement”). The Prospectus as supplemented by various Prospectus Supplements will provide for the registration by the Company of up to $200,000,000 aggregate offering price of (i) shares of common stock, par value $0.01 per share (the “Common Stock”), (ii) one or more series of secured or unsecured debt securities, which may be either senior, senior subordinated or subordinated debt securities (the “Debt Securities”), and (iii) warrants to purchase Common Stock or Debt Securities (the “Warrants”), or any combination of the foregoing, plus any additional Common Stock, Debt Securities or Warrants that may be registered pursuant to any subsequent registration statements that the Company may hereafter file with the Commission pursuant to Rule 462(b) under the Securities Act (collectively, the “Securities”). Any Debt Securities may be exchangeable and/or convertible into shares of Common Stock or into other securities. The Debt Securities may be issued pursuant to an indenture between the Company and a financial institution to be identified therein as trustee (the “Trustee”) in the form included as Exhibit 4.1 to the Registration Statement, as such indenture may be supplemented from time to time (the “Indenture”). The Warrants may be issued under one or more warrant agreements (each, a “Warrant Agreement”) between the Company and a bank or trust company to be identified therein as warrant agent (each, a “Warrant Agent”).

Ceradyne, Inc.

November 15, 2005

Page Two

In our capacity as your counsel in connection with such registration, we are familiar with the proceedings taken and proposed to be taken by the Company in connection with the authorization of the Indenture and the authorization, issuance and sale of the Securities. For the purposes of this opinion, we have assumed that such proceedings to be taken in the future will be timely completed in the manner presently proposed and that the terms of each issuance will otherwise be in compliance with law. In addition, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter.

We are opining herein as to the effect on the subject transaction only of the General Corporation Law of the State of Delaware, and with respect to the opinions set forth in paragraphs 2 through 4 below, the internal laws of the State of New York, and we express no opinion with respect to the applicability thereto, or the effect thereon, of the laws of any other jurisdiction or, in the case of Delaware, any other laws, or as to any matters of municipal law or the laws of any local agencies within any state.

Subject to the foregoing and the other matters set forth herein, it is our opinion that as of the date hereof:

1. When the Registration Statement and any required post-effective amendments thereto have all become effective under the Securities Act and any and all Prospectus Supplement(s) required by applicable laws have been delivered and filed as required by such laws, and upon adoption by the Board of Directors of the Company of a resolution in form and content as required by applicable law authorizing the issuance of such shares and upon issuance and delivery of and payment of legal consideration not less than the par value thereof for shares of Common Stock in the manner contemplated by the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and by such resolution, and assuming that (i) the terms of such shares as issued and delivered are as described in the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and such resolution, (ii) at the time of issuance of such shares, the Company has a sufficient number of authorized but unissued shares under the Company’s Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), (iii) such shares as issued and delivered comply with all requirements and restrictions, if any, applicable to the Company, whether imposed by any court or governmental or regulatory body having jurisdiction over the Company or otherwise and (iv) such shares are then issued and sold as contemplated in the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and such resolution, such shares of Common Stock (including any Common Stock duly issued upon the exercise of any Warrants pursuant to the terms thereof that are exercisable for the purchase of Common Stock or upon the exchange or conversion of Debt Securities that are exchangeable or convertible into Common Stock) will be validly issued, fully paid and nonassessable.

2. When (i) the Indenture has been duly authorized, executed and delivered by the Company and the Trustee, and (ii) the Debt Securities have been duly authorized and duly established in accordance with the Indenture and applicable law (including, without limitation, by the adoption by the Board of Directors of the Company of a resolution duly authorizing the issuance and

Ceradyne, Inc.

November 15, 2005

Page Three

delivery of the Debt Securities) (the “Debt Securities Authorization”), duly authenticated by the Trustee and duly executed and delivered on behalf of the Company against payment therefor in accordance with the terms and provisions of the Indenture and as contemplated by the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and the Debt Securities Authorization, and (iii) the Registration Statement and any required post-effective amendments thereto have all become effective under the Securities Act and any and all Prospectus Supplement(s) required by applicable laws have been delivered and filed as required by such laws, and assuming that (a) the terms of the Debt Securities as executed and delivered are as described in the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and the Debt Securities Authorization, (b) the Debt Securities as executed and delivered do not violate any law applicable to the Company or result in a default under or breach of any agreement or instrument binding upon the Company, (c) the Debt Securities as executed and delivered comply with all requirements and restrictions, if any, applicable to the Company, whether imposed by any court or governmental or regulatory body having jurisdiction over the Company or otherwise, and (d) the Debt Securities are then issued and sold as contemplated in the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and the Debt Securities Authorization, the Debt Securities (including any Debt Securities duly issued (i) upon the exchange or conversion of any Debt Securities that are exchangeable or convertible into another series of Debt Securities or (ii) upon the exercise of any Warrants pursuant to the terms thereof that are exercisable for the purchase of Debt Securities) will constitute legally valid and binding obligations of the Company, enforceable against the Company in accordance with their terms.

3. When (i) the Registration Statement and any required post-effective amendments thereto have all become effective under the Securities Act and any and all Prospectus Supplement(s) required by applicable laws have been delivered and filed as required by such laws, (ii) the applicable Warrant Agreement has been duly authorized, executed and delivered by the Company and the Warrant Agent, (iii) the Warrants have been duly authorized and duly established in accordance with the terms of the Warrant Agreement and applicable law (including, without limitation, by the adoption by the Board of Directors of the Company of a resolution duly authorizing the issuance and delivery of the Warrants) (the “Warrant Authorization”) and (iv) the Warrants have been duly executed, authenticated and/or countersigned in accordance with the Warrant Agreement relating to such Warrants and delivered on behalf of the Company against payment therefor (which, in the case of Warrants for Common Stock, shall consist of legal consideration not less than the par value of such shares) as contemplated by the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and the Warrant Authorization, and assuming that (a) the terms of the Warrants as executed and delivered are as described in the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and the Warrant Authorization, (b) the Warrants as executed and delivered do not violate any law applicable to the Company or result in a default under or breach of any agreement or instrument binding upon the Company, (c) the Warrants as executed and delivered comply with all requirements and restrictions, if any, applicable to the Company, whether imposed by any court or governmental or regulatory body having jurisdiction over the Company or otherwise and (d) the Warrants are then issued and sold as contemplated by the Registration Statement, the Prospectus and the related Prospectus Supplement(s) and the Warrant

Ceradyne, Inc.

November 15, 2005

Page Four

Authorization, the Warrants will constitute legally valid and binding obligations of the Company, enforceable against the Company in accordance with their terms.

4. When (i) the Registration Statement and any required post-effective amendments thereto have all become effective under the Securities Act and any and all Prospectus Supplement(s) required by applicable laws have been delivered and filed as required by such laws, and (ii) the Indenture has been duly authorized, executed and delivered by the Company and the Trustee, and (iii) assuming that the Indenture does not violate any law applicable to the Company or result in a default under or breach of any agreement or instrument binding upon the Company, and (iv) assuming that the Indenture complies with all requirements and restrictions, if any, applicable to the Company, whether imposed by any court or governmental or regulatory body having jurisdiction over the Company or otherwise, the Indenture will constitute the legally valid and binding obligation of the Company, enforceable against the Company in accordance with its terms.

The opinions set forth in paragraphs 2, 3 and 4 relating to the enforceability of the Debt Securities, the Warrants and the Indenture, respectively, are subject to the following exceptions, limitations and qualifications: (i) the effect of bankruptcy, insolvency, reorganization, preference, fraudulent transfer, moratorium or other similar laws relating to or affecting the rights and remedies of creditors; and (ii) the effect of general principles of equity, whether enforcement is considered in a proceeding in equity or at law (including the possible unavailability of specific performance or injunctive relief), concepts of materiality, reasonableness, good faith and fair dealing, and the discretion of the court before which any proceeding therefor may be brought.

The opinions expressed herein as to Debt Securities do not include (i) any opinion with respect to the creation, validity, perfection or priority of any security interest or lien, or (ii) any opinion with respect to compliance with laws relating to permissible rates of interest.

We have not been requested to express and, with your consent, do not render any opinion as to the applicability to the obligations of the Company under the Indenture or the Debt Securities of Sections 547 and 548 of the United States Bankruptcy Code or applicable state law relating to preferences and fraudulent transfers and obligations.

Ceradyne, Inc.

November 15, 2005

Page Five

With your consent, we have assumed for purposes of this opinion that (i) each of the parties to the Indenture and any Warrant Agreement (collectively the “Operative Documents”) other than the Company (a) is duly organized, validly existing and in good standing under the laws of its jurisdiction of organization; (b) has the requisite power and authority to execute and deliver and to perform its obligations under each of the Operative Documents to which it is a party; and (c) has duly authorized, executed and delivered each such Operative Document; (ii) with respect to each of the parties to the Operative Documents other than the Company, each Operative Document to which it is a party constitutes its legally valid and binding agreement, enforceable against it in accordance with its terms; (iii) the Trustee is in compliance, generally and with respect to acting as Trustee under the Indenture, with all applicable laws and regulations; and (iv) the Warrant Agent is in compliance, generally and with respect to acting as warrant agent under the Warrant Agreement, with all applicable laws and regulations.

We consent to the use of this opinion as an exhibit to the Registration Statement and to the use of our name under the caption “Legal Matters” in the Prospectus which is part of the Registration Statement.

Very truly yours,

STRADLING YOCCA CARLSON & RAUTH

/s/ Stradling Yocca Carlson & Rauth

EX-12.1

Exhibit 12.1

Calculation of Ratio of Earnings to Fixed Charges

	Year Ended December 31,
	2000		2001		2002		2003		2004		Nine Months Ended September 30, 2005
	(In thousands, except ratio of earnings to fixed charges)
Income from continuing operations before income taxes	$	5,197	$	4,837	$	4,132	$	17,288	$	43,919	$	48,689
Fixed charges(1)
Interest expense		34		26		102		32		1,661		4,987
Amortization of debt issuance cost		—		—		—		—		253		566
Interest included in rental expense		230		264		365		350		425		473
Total fixed charges	$	264	$	290	$	467	$	382	$	2,339	$	6,026
Earnings(2)	$	5,461	$	5,127	$	4,599	$	17,670	$	46,258	$	54,715
Ratio of earnings to fixed charges		20.7		17.7		9.8		46.3		19.8		9.1

(1) “Fixed charges” consist of interest expense on indebtedness, amortization of debt issuance costs and the estimated portion of rental expense deemed a reasonable approximation of this interest factor.

(2) “Earnings” consist of income from continuing operations before income taxes plus fixed charges.

EX-23.1

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-3 of our report dated March 16, 2005 relating to the financial statements, management’s assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting, which appears in Ceradyne, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2004. We also consent to the reference to us under the headings “Experts” in such Registration Statement.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Orange County, CA

November 15, 2005

EX-23.2

Exhibit 23.2

CONSENT OF INDEPENDENT PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference herein of our report dated July 30, 2004, with respect to the combined balance sheets of ESK Ceramics GmbH & Co. KG as of December 31, 2003 and 2002 and the related combined statements of operations, partners’ equity, and cash flows for each of the years in the three-year period ended December 31, 2003, which report appears in the Form 8-K/A of Ceradyne, Inc. dated November 8, 2004 and to the reference to our firm under the headings “Experts” in the registration statement.

/s/ KPMG Deutsche Treuhand-Gesellschaft

Aktiengesellschaft Wirtschaftsprufungsgesellschaft

Munich, Germany

November 15, 2005

CORRESP

WRITTEN RESPONSES TO SEC STAFF COMMENTS

DATED NOVEMBER 10, 2005

Ceradyne, Inc., a Delaware corporation (the “Company”), in connection with the filing of its Amendment No. 1 to Registration Statement on Form S-3, Registration No. 333-129197, hereby responds to the SEC Staff comments made by letter dated November 10, 2005. The Company’s responses are keyed by numbered paragraphs to correspond to the comments made by the SEC Staff in the November 10, 2005 letter. Each response is preceded by a reproduction of the corresponding SEC Staff comment.

General

1. At the time the company requests acceleration of this registration statement, the company should state that it has no present intent to make the first offering of securities promptly, and therefore will be making the offering on a delayed basis rather than in reliance on Rule 430A. Alternatively, the company should file a pre-effective amendment to include all of the information about the securities to be offered, plan of distribution, a clean legality opinion and, if applicable, an underwriting agreement with regard to any securities to be offered promptly, including in reliance on Rule 430A.

Response 1. The Company acknowledges the Staff’s comments and will comply accordingly.

Calculation of Registration Fee Table

2. We reference footnote 3. Please confirm that as shares of the underlying common stock are offered and sold, you will count them against the dollar amount of the securities remaining on this registration statement.

Response 2. The Company supplementally confirms that as shares of the underlying common stock are offered and sold, the Company will count such shares against the dollar amount of the securities remaining on the Registration Statement.

Risk Factors, page 1

3. Please delete the second and third sentences of the first paragraph. All material risks should be described. If risks are not deemed material, you should not reference them.

Response 3. In response to the Staff’s comment, the Company has deleted the second and third sentences of the first paragraph under the heading “Risk Factors” on page 1.

Ceradyne, Inc.

Written Responses to SEC Staff Comments

Page 2

4. Please note that it may be appropriate to include risk factors in your takedown supplements on issues specific to the securities such as the lack of an intention to list the debt securities on any trading market.

Response 4. The Company acknowledges the Staff’s comment will include appropriate risk factor disclosures in its takedown supplements.

Use of Proceeds, page 4

5. Supplementally confirm to us that your takedown supplements will disclose the amount and terms of debt you may pay off with proceeds from the sale of the securities.

Response 5. The Company supplementally confirms to the Staff that its takedown supplements will disclose the amount and terms of debt it may pay off with proceeds from the sale of the securities.

Description of Debt Securities, page 5

6. Delete the statement on page 9 that you take no responsibility for the accuracy of the information you provide concerning DTC. We would not object if you noted that you are not responsible for the performance of DTC of its obligations under the rules and procedures governing its operations.

Response 6. In response to the Staff’s comment, the Company has deleted the statement on page 9 referenced in the Staff’s comment and has added a statement to the effect that the Company is not responsible for the performance of DTC of its obligations under the rules and procedures governing DTC’s operations.

7. We advise you that the debt securities may not be convertible into “other securities” that have not been registered under this registration statement unless the debt securities convertible into such other securities are not legally convertible immediately or within one year of the date of sale of the debt securities. All of the underlying classes of securities must be identified in the registration statement.

Response 7. The Company acknowledges and agrees with the Staff’s comment.

Plan of Distribution, page 15

8. Rule 415(a)(4) requires that in an “at the market” equity offering by a registrant, the underwriter must be named in a prospectus that is “part of the registration statement.” If you intend to conduct such an offering prior to December 1^st, please clarify that prior to December 1^st, a post-effective amendment will be filed to name underwriters. On or after December 1^st, an issuer that meets the conditions of the revised provisions of Rule 415(a)(4) for such offerings would not have to file a post-effective amendment for such purposes.

Ceradyne, Inc.

Written Responses to SEC Staff Comments

Page 3

Response 8. The Company acknowledges and agrees that if it intends to conduct an “at the market” offering prior to December 1^st it will file a post-effective amendment to name the underwriters prior to such date.

9. We note your disclosure that third parties may engage in short sales in your securities. Supplementally confirm that you are aware of Telephone Interp. A.65 (July 1997) on this matter, which is publicly available on our website, and revise your disclosure accordingly.

Response 9. The Company supplementally confirms to the Staff that it is aware of Telephone Interp. A.65 (July 1997) with regard to short sales by third parties of the Company’s securities. In response to the Staff’s comment, the Company has revised the disclosure on page 16 accordingly.

Legal Matters, page 17

10. Please confirm to us that you will file a clean opinion, either in post-effective amendment or in a Form 8-K, for each takedown.

Response 10. The Company supplementally confirms to the Staff that the Company will file a clean opinion, either in a post-effective amendment or in a Form 8-K, for each takedown.

Exhibit 5.1 – Legal Opinion

11. Since the indenture is governed by the laws of New York, the opinion cannot be limited to Delaware law. Counsel must also opine that the warrants are binding obligations under the state contract law governing the warrant agreement. Please revise.

Response 11. In response to the Staff’s comment, Company counsel has revised the legal opinion to include the application of the laws of New York with respect to the indenture, the warrants and the debt securities.

12. Please delete as inappropriate, the enforceability qualifications in clauses (iii)-(vii).

Response 12. In response to the Staff’s comment, Company counsel has deleted the enforceability qualifications in clauses (iii)-(vii) of its legal opinion.