$ 500,000                                                     New York, New York
                                                                   June 23, 1997

                                 PROMISSORY NOTE

      THIS PROMISSORY NOTE is made in New York, New York, as of June 23, 1997
(this "Note"), for Five Hundred Thousand Dollars ($500,000). Capitalized terms
used herein without definition shall have the meaning ascribed to them in the
Stockholders' Agreement of even date herewith among Roller Bearing Holding
Company, Inc. ("Holdings") and certain of its stockholders, as in effect on the
date herewith.

                                    RECITALS:

      This Note is made by Michael J. Hartnett, Ph.D. ("Maker"), and is payable
to Roller Bearing Company of America, Inc., a Delaware Corporation with a
principal place of business at 60 Round Hill Road, Fairfield, Connecticut
("Payee").

      This Note evidences the obligation of Maker to pay to Payee the principal
amount of Five Hundred Thousand Dollars ($500,000).

      NOW THEREFORE, in consideration of the foregoing and for other good and
valuable consideration the receipt, the adequacy and sufficiency of which are
hereby acknowledged, the Maker makes this Note as follows:

      1. Payment.

      (a) Maker hereby promises to pay to Payee the then principal balance
hereof as well as any other amounts due hereunder on the earlier to occur of (i)
the first to occur of (A) an Initial Public Offering, or (B) any sale of
business transaction involving Holdings and all of its subsidiaries, taken as a
whole, whether in the nature of a sale of all or substantially all of their
assets; a sale of all of the Securities; or a merger, recapitalization or
reorganization following which the holders of Securities prior to such event no
longer own any Securities or any voting securities in the surviving or successor
entity, and (ii) June 23, 2007.

      (b) The Payee shall have no rights of offset under any circumstances
whatsoever, i.e. regardless of the circumstances under which Payee is obligated
to the Maker; pursuant thereto, except as set forth in the first sentence of
this subsection (b), Payee may not satisfy any obligations that it may have to
Maker by offset against, or reduction of, amounts due hereunder.

      (c) This Note shall not bear interest.


      2. Pledge. The Maker acknowledges that he is utilizing the proceeds hereof
to acquire 972.763 shares of Class A Common Stock that will have been exchanged
for 972.763 shares of Class B Supervoting Common Stock (the "Pledged Shares").
The Maker hereby confirms his agreement to pledge the Pledged Shares as security
for repayment of amounts due hereunder. Maker hereby agrees to execute such
pledge agreement as the Payee may reasonably request to evidence such pledge.

      3. Default and Remedies.

      (a) In the event default is made in the payment of this Note and such
default continues for five (5) days after such due date (an "Event of Default"),
Payee shall have the option to exercise any and all rights and remedies
available at law or in equity or under any document or instrument securing this
Note. If suit is brought to collect the amount due under this Note, Payee shall
be entitled to collect from Maker all reasonable costs and expenses of suit,
including, but not limited to, reasonable attorneys' fees.

      (b) The remedies of Payee shall be cumulative and concurrent, and may be
pursued singularly, successively or together, at the sole discretion of Payee.
No act or omission or commission of Payee, including specifically any failure to
exercise any right, remedy or recourse, shall be deemed to be a waiver or
release of the same, such waiver or release to be effected only through a
written document executed by Payee and then only to the extent specifically
recited therein.

      4. Waiver.

      The Maker hereby waives presentment and demand for payment, notice of
dishonor, protest and notice of protest of this Note.

      5. Miscellaneous.

      (a) The headings of the paragraphs of this Note are inserted for
convenience only and shall not be deemed to constitute a part hereof.

      (b) All payments under this Note shall be payable in lawful money of the
United States which shall be legal tender for public and private debts at the
time of payment and shall be paid to Payee at its principal place of business at
60 Round Hill Road, Fairfield, Connecticut.

      (c) This Note shall be governed by and construed under the laws of the
State of New York.

      (d) This Note shall be binding upon and inure to the benefit of the
parties hereto and their respective successors and assigns, except that Maker
shall not have the right to assign the


obligations made under this Note without the prior written consent of Payee.

      IN WITNESS WHEREOF, Maker has executed and delivered this Note as of the
date and year first above written.


                                             -----------------------------------
                                             Michael J. Hartnett, Ph.d.