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                                                                    EXHIBIT 10.3

                                JOINDER AGREEMENT

         THIS BORROWER JOINDER AGREEMENT (the "Agreement"), dated as of
September 27, 2002, is by and among WOLVERINE JOINING TECHNOLOGIES, LLC, a
Delaware limited liability company, SMALL TUBE MANUFACTURING, LLC, a Delaware
limited liability company and WOLVERINE FINANCE, LLC, a Tennessee limited
liability company (each an "Applicant Borrower" and collectively, the "Applicant
Borrowers"), WOLVERINE TUBE, INC., a Delaware corporation (the "Company"), and
WACHOVIA BANK, NATIONAL ASSOCIATION, in its capacity as Administrative Agent
under that certain Credit Agreement (as amended and modified, the "Credit
Agreement"), dated as of March 27, 2002, by and among the Company, and certain
of the Company's U.S. and Canadian Subsidiaries (collectively, the "Credit
Parties"), the Lenders party thereto, the Administrative Agent, and Congress
Financial Corporation (Canada), as Canadian Agent. All of the defined terms in
the Credit Agreement are incorporated herein by reference.

         Each Applicant Borrower has indicated its desire to become a Borrower
pursuant to the terms of the Credit Agreement.

         Accordingly each Applicant Borrower hereby agrees as follows with the
Administrative Agent, for the benefit of the Lenders:

         1.       Each Applicant Borrower hereby acknowledges, agrees and
confirms that, by its execution of this Agreement, such Applicant Borrower will
be deemed to be a party to the Credit Agreement and a "Borrower" for all
purposes of the Credit Agreement and the other Credit Documents, and shall have
all of the obligations of a Borrower thereunder as if it has executed the Credit
Agreement and the other Credit Documents. Each Applicant Borrower hereby
ratifies, as of the date hereof, and agrees to be bound by, all of the terms,
provisions and conditions contained in the Credit Agreement and in the Credit
Documents, including without limitation (i) all of the representations and
warranties of the Credit Parties set forth in Article VI of the Credit
Agreement, as supplemented from time to time in accordance with the term
thereof, and (ii) all of the affirmative and negative covenants set forth in
Articles VII, VIII and IX of the Credit Agreement.

         2.       Each Applicant Borrower hereby acknowledges, agrees and
confirms that, by its execution of this Agreement, such Applicant Borrower will
be deemed to be a party to the U.S. Security Agreement, and shall have all the
obligations of an "Obligor" (as such term is defined in the U.S. Security
Agreement) thereunder as if it had executed the U.S. Security Agreement. Each
Applicant Borrower hereby ratifies, as of the date hereof, and agrees to be
bound by, all of the terms, provisions and conditions contained in the U.S.
Security Agreement. Without limiting generality of the foregoing terms of this
paragraph 2, each Applicant Borrower hereby grants to the Agent, for the benefit
of the Lenders, a continuing security interest in, and a right of set off
against any and all right, title and interest of such Applicant Borrower in and
to the Collateral (as such term is defined in Section 2 of the U.S. Security
Agreement) of such Applicant Borrower.

         3.       Each Applicant Borrower hereby acknowledges, agrees and
confirms that, by its execution of this Agreement, such Applicant Borrower will
be deemed to be a party to the

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Guaranty Agreement, and shall have all the obligations of a Guarantor (as such
term is defined in the Credit Agreement) thereunder as if it had executed the
Guaranty Agreement. Each Applicant Borrower hereby ratifies, as of the date
hereof, and agrees to be bound by, all of the terms, provisions and conditions
applicable to the Guarantors contained in the Guaranty Agreement. Without
limiting generality of the foregoing terms of this paragraph 3, each Applicant
Borrower hereby (i) jointly and severally together with the other Guarantors,
guarantees to each Lender and the Agent, as provided in Section 1 of the
Guaranty Agreement, the prompt payment of the Indebtedness (as defined in the
Guaranty Agreement) in full when due (whether at stated maturity, as a mandatory
prepayment, by acceleration or otherwise) strictly in accordance with the terms
thereof.

         4.       Each Applicant Borrower acknowledges and confirms that it has
received a copy of the Credit Agreement and the schedules and exhibits thereto,
the U.S. Security Agreement and the schedules and exhibits relating thereto and
the Guaranty Agreement. The information on the Schedules to the Credit Agreement
and each of the Security Documents are amended to provide the information shown
on the attached Schedule A.

         5.       The Company confirms that all of its and its Subsidiaries'
obligations under the Credit Agreement are, and upon each Applicant Borrower
becoming a Borrower shall continue to be, in full force and effect. The Company
further confirms that immediately upon each Applicant Borrower becoming a
Borrower the term "Obligations", as used in the Credit Agreement, shall include
all Obligations of the Applicant Borrowers under the Credit Agreement and under
each other Credit Document.

         6.       Each Applicant Borrower hereby agrees that upon becoming a
Borrower it will assume all Obligations of a Borrower as set forth in the Credit
Agreement. By its execution of this Agreement, each of the Applicant Borrowers
appoints each of James E. Deason, Vice Manager of Wolverine Finance, LLC and
Vice President of Wolverine Joining Technologies, LLC and Small Tube
Manufacturing, LLC and Johann R. Manning, Jr., Vice Manager and Secretary of
Wolverine Finance, LLC and Vice President and Secretary of Wolverine Joining
Technologies, LLC and Small Tube Manufacturing, LLC, of the Company, to be its
respective attorneys ("its Attorneys") and in its name and on its behalf and as
its act and deed or otherwise to sign all documents and carry out all such acts
as are necessary or appropriate in connection with executing any Notice of
Borrowing, Notice of Extension/Conversion or any Borrowing Base Certificate or
any security documents (the "Documents") in connection with the Credit
Agreement, provided that such Documents are in substantially the form provided
therefor in the applicable exhibits thereto. This Power of Attorney shall be
valid for the duration of the term of the Credit Agreement. Each Applicant
Borrower hereby undertakes to ratify everything which either of its Attorneys
shall do in order to execute the Documents mentioned herein.

         7.       Each of the Company and each of the Applicant Borrowers agrees
that at any time and from time to time, upon the written request of the
Administrative Agent, it will execute and deliver such further documents and do
such further acts and things as the Administrative Agent may reasonably request
in order to effect the purposes of this Agreement.

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         8.       This Agreement may be executed in two or more counterparts,
each of which shall constitute an original but all of which when taken together
shall constitute one contract.

         9.       This Agreement shall be governed by and construed and
interpreted in accordance with the laws of the State of North Carolina.

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         IN WITNESS WHEREOF, each of the Applicant Borrowers and the Company has
caused this Borrower Joinder Agreement to be duly executed by its authorized
officers, and the Administrative Agent, for the benefit of the Lenders, has
caused the same to be accepted by its authorized officer, as of the day and year
first above written.

                                    WOLVERINE JOINING TECHNOLOGIES, LLC



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

                                    SMALL TUBE MANUFACTURING, LLC



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

                                    WOLVERINE FINANCE, LLC



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

                                    WOLVERINE TUBE, INC.



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


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                                    WACHOVIA BANK, NATIONAL ASSOCIATION,
                                      as Administrative Agent



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

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                                   SCHEDULE A
                                       to
                           Borrower Joinder Agreement

                          Schedules to Credit Agreement
                          (to be updated as necessary)

                     Schedule 4(a)(i) to Security Agreement
      Chief Executive Office/Principal Place of Business/State of Formation

                     Schedule 4(a)(ii) to Security Agreement
             Name Changes/Changes in Corporate Structure/Tradenames

                       Schedule 4(b) to Security Agreement
                             Locations of Collateral

                        Schedule 2(a) to Pledge Agreement
                                  Pledged Stock