SUPPLEMENTAL INDENTURE

            SUPPLEMENTAL INDENTURE (this "Supplemental Indenture"), dated as of
August 8, 1997, by and between Bremen Bearings, Inc. (the "Bremen") and United
States Trust Company of New York, a New York trust company (the "Trustee").

                                    RECITALS:

            WHEREAS, pursuant to that certain Indenture (the "Existing
Indenture"), dated as of June 15, 1997, a copy of which is attached hereto as
Schedule 1, among Roller Bearing Company of America, Inc. ("RBCA"), Industrial
Tectonics Bearings Corporation ("ITB"), RBC Linear Precision Products, Inc.
("LPP"), RBC Nice Bearings, Inc. ("Nice") and the Trustee, RBCA has issued and
ITB, LPP and Nice have guaranteed RBCA's 9-5/8% Senior Subordinated Notes Due
2007 (the "Notes"); and

            WHEREAS, Bremen wishes to join in the guarantee of the obligations
of RBCA under the Notes, all on the terms and conditions set forth in the
Existing Indenture.

            NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, it is agreed as follows:

            1. Joinder to Existing Indenture. Bremen hereby joins in the
Existing Indenture in accordance with Section 4.10 of the Existing Indenture,
agrees to be bound by the Existing Indenture for all purposes as a Subsidiary
Guarantor thereunder, including, without limitation, for the purposes of the
undertakings contained in Articles 11 and 12 thereof, all as if Bremen were an
original party thereto.

            2. Entire Agreement. Bremen and the Trustee hereby acknowledge that
this Indenture and the Existing Indenture embody the entire agreement and
understanding of Bremen and the other parties to the Existing Indenture in
respect of the subject matter contained herein or therein. There are no
agreements, representatives, warranties or covenants other than those expressly
set forth herein or therein. This Indenture and the Indenture supersede all
prior agreements and understandings between the parties hereto, whether written
or oral, express or implied, with respect to such subject matter herein or
therein.

            3. Binding Effect. This Indenture shall take effect as of the date
and year first above written and shall be binding upon the parties hereto and
shall be binding on their respective heirs, executors, administrators, personal
representatives, successors and assigns, as the case may be. The parties hereto
may not assign or transfer any of their rights or obligations under this
Indenture.



            4. Governing Law. This Indenture shall be governed by, construed and
enforced in accordance with the internal laws of the State of New York, without
regard to the conflicts of laws principles thereof.

            IN WITNESS WHEREOF, the undersigned have executed this Indenture as
of the day and year first written above.

                                          BREMEN BEARINGS, INC.


                                          By:
                                             ------------------------
                                             Michael J. Hartnett
                                             President


                                          UNITED STATES TRUST COMPANY
                                          OF NEW YORK


                                          By:
                                             ------------------------
                                             Name:
                                             Title:


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