<PAGE>   1
                                                                EXHIBIT 10.30.1

                       AMENDMENT NO. 1 TO CREDIT AGREEMENT

THIS AMENDMENT NO. 1 TO CREDIT AGREEMENT (this "Agreement") is made and entered
into as of July 13 2000 among each of MEDICAL DEVICE MANUFACTURING, INC., a
Colorado corporation (the "Borrower"), MDMI HOLDINGS, INC., a Colorado
corporation (the "Parent"), EACH OF THE SUBSIDIARY GUARANTORS (collectively, the
"Subsidiary Guarantors" and together with the Parent, the "Guarantors" and each
a "Guarantor"), BANK OF AMERICA, N.A., a national banking association organized
and existing under the laws of the United States, in its capacity as a Lender
("Bank of America"), and each other financial institution executing and
delivering a signature page hereto (hereinafter such financial institutions may
be referred to individually as a "Lender" or collectively as the "Lenders"),
BANK OF AMERICA, N.A., a national banking association organized and existing
under the laws of the United States, in its capacity as administrative agent for
the Lenders (in such capacity, the "Agent"), FLEET NATIONAL BANK, as Syndication
Agent (in such capacity, "Fleet"), and DRESDNER BANK AG, NEW YORK BRANCH AND
GRAND CAYMAN BRANCH, as Documentation Agent (in such capacity, "Dresdner").

                                  WITNESSETH:

         WHEREAS, the Borrower, the Lenders, the Agent, Fleet and Dresdner have
entered into that certain Credit Agreement dated as of May 31, 2000 (the "Credit
Agreement"), pursuant to which the Lenders have made and agreed to make certain
Loans to, and issue Letters of Credit for the account of, the Borrower; and

         WHEREAS, the Agent and the Subsidiary Guarantors have entered into a
Guaranty Agreement dated as of May 31, 2000 (the "Subsidiary Guaranty") pursuant
to which the Subsidiary Guarantors have guaranteed payment of the Borrower's
Liabilities (as defined in the Subsidiary Guaranty); and

         WHEREAS, the Agent and the Parent have entered into a Guaranty
Agreement dated as of May 31, 2000 (the "Parent Guaranty") pursuant to which the
Parent has guaranteed payment of the Borrower's Liabilities (as defined in the
Parent Guaranty); and

         WHEREAS, the Agent and the Lenders have requested that the Borrower
consent to certain amendments to the Credit Agreement as specified below; and

         WHEREAS, subject to the terms and conditions specified below, the Agent
and the Lenders are willing to consent to the requested amendments;

         NOW, THEREFORE, in consideration of the mutual covenants and the
fulfillment of the conditions set forth herein, the parties hereto do hereby
agree as follows:

         1. Definitions. Any capitalized term used herein without definition
shall have the meaning set forth in the Credit Agreement.


<PAGE>   2

         2. Amendments to the Credit Agreement. Subject to the terms and
conditions set forth herein, the Credit Agreement is hereby amended as follows:

               (a) The definition of "Adjusted Consolidated Fixed Charge Ratio"
          in Section 1.1 is amended by inserting the words "(except to the
          extent of any increase in Consolidated EBITDA for such period as a
          result of any prior Earnout Payment)" immediately after the words "to
          which such calculation relates" in the sixth line thereof.

               (b) The definition of "Consolidated Fixed Charges" in Section 1.1
          is amended by inserting the words ", or stock repurchase, redemption,
          retirement conversion, exchange or other acquisition under Section
          10.9(a)," immediately after the words "any dividends" in the clause
          (iii) thereof.

               (c) The definition of "Earnout Equity Contribution" in Section
          1.1 is amended by inserting the words "the Parent and then by the
          Parent to" immediately after the words "any cash equity contribution
          to" in the first line thereof.

               (d) The definition of "Excess Cash Flow" in Section 1.1 is
          amended by deleting the words "and required repayments of principal of
          the Term Loans during such period" in clause (D) thereof.

               (e) The definition of "Obligations" in Section 1.1 is amended by
          inserting the words "or their affiliates" after the words "to the
          Lenders" in the sixth line thereof.

               (f) The definition of "Required Lenders" in Section 1.1 is
          amended by inserting the words "Applicable Commitment Percentage of"
          immediately before the words "Term Loan Outstandings" in clause (a)
          thereof.

               (g) Section 2.1(d) of the Credit Agreement is amended by adding
          the words "pro rata to the Term Loans and" immediately following the
          word "applied" in the next to last line thereof.

               (h) Section 8.4 of the Credit Agreement is amended by deleting
          the first sentence thereof and inserting the following in replacement
          thereof:

               As of the Closing Date, the Parent and the Borrower have no
               Subsidiaries other than those Persons listed as Subsidiaries in
               Schedule 8.4.

               (i) Section 10.9(a) of the Credit Agreement is amended deleting
          the words "the Borrower or its Subsidiaries" and by inserting the
          words "the Parent," immediately following the words "shares of capital
          stock issued by" in the third line thereof.

               (j) Section 11.1(e) of the Credit Agreement is amended by
          deleting the brackets surrounding the dollar figure "$375,000" in the
          fourth line thereof.

                                       2

<PAGE>   3

               (k) Section 12.5 of the Credit Agreement is amended by inserting
          the words ", unless such action required the unanimous consent of all
          Lenders which was not obtained" immediately following the words
          "willful misconduct" in the second proviso thereof.

               (l) Article XIII of the Credit Agreement is amended by adding a
          new Section 13.17 at the end thereof which shall read as follows:

                    13.17 Term Loan Lender.Each of the parties hereto
               acknowledges and agrees that neither of Antares Capital
               Corporation (together with its successors and assigns, "Antares")
               nor Chase Bank of Texas, National Association, as Trustee of the
               Antares Funding Trust created under Trust Agreement dated as of
               November 30, 1999 (together with its successors and assigns, the
               "CLO") will have any Revolving Credit Commitment hereunder
               notwithstanding the provisions of Section 13.1(a)(iii). The
               parties hereto agree that any reference to a "Lender" in Sections
               2.2, 2.5 or 4.6 or Article III hereof shall be deemed not to
               include Antares or the CLO and that neither Antares nor the CLO
               shall have any obligation as a Lender to fund any Revolving Loan.

         3. Conditions Precedent. This amendment shall become effective only
upon the receipt by the Agent of the following, in form and substance
satisfactory to the Agent:

               (a) originals of this Agreement executed by the Borrower, the
          Guarantors and the Lenders;

               (b) evidence that all fees payable by the Borrower to the Agent
          and the Lenders of the date of this Agreement have been paid in full;

               (c) copies of all additional agreements, instruments and
          documents which the Lenders may reasonably request, such documents,
          when appropriate, to be certified by appropriate governmental
          authorities.

         4. Consent of Guarantors. Each of the Guarantors has joined in the
execution of this Amendment solely for the purposes of consenting hereto and for
the further purpose of confirming its guaranty of payment of the Borrower's
Liabilities pursuant to the Facility Guaranty and all security granted therefor,
and each such Guarantor does hereby so consent hereto and confirm and ratify
such guaranty and grant of security.

         5. Representations and Warranties. In order to induce the Agent and the
Lenders to enter into this Agreement, the Borrower and the Guarantors represent
and warrant to the Agent and the Lenders as follows:

               (a) The representations and warranties made by the Borrower or
          Guarantor in Article VIII of the Credit Agreement and in each of the
          other Loan Documents to which it is a party after giving effect to the
          transactions contemplated by Amendment

                                       3

<PAGE>   4

          Documents are true and correct in all material respects on and as of
          the date hereof, except to the extent that such representations and
          warranties expressly relate to an earlier date (in which case they
          continue to be true as of such earlier date);

               (b) There has been no material adverse change in the condition,
          financial or otherwise, of the Borrower and its Subsidiaries, taken as
          a whole, since the date of the most recent financial reports of the
          Borrower received by each Agent and the Lenders under Section 9.1 of
          the Credit Agreement; and

               (c) No Default or Event of Default has occurred and is
          continuing.

         6. Full Force and Effect of Agreement. Except as hereby specifically
amended, modified or supplemented, the Credit Agreement and all other Loan
Documents are hereby confirmed and ratified in all respects by each party hereto
and shall be and remain in full force and effect according to their respective
terms.

         7. Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original as against any party
whose signature appears thereon, and all of which shall together constitute one
and the same instrument.

         8. Governing Law. This Agreement shall in all respects be governed by,
and construed in accordance with, the laws of the state of New York.

         9. Enforceability. Should any one or more of the provisions of this
Agreement be determined to be illegal or unenforceable as to one or more of the
parties hereto, all other provisions nevertheless shall remain effective and
binding on the parties hereto.

         10. References. All references in any of the Loan Documents to the
"Credit Agreement" shall mean the Credit Agreement as amended hereby.

         11. Successors and Assigns. This Agreement shall be binding upon and
inure to the benefit of the Borrower, the Guarantors, the Lenders, the Agent and
their respective successors, assigns and legal representatives; provided,
however, that the Borrower and the Guarantors, without the prior consent of the
Lenders, may not assign any rights, powers, duties or obligations hereunder.


                            [SIGNATURE PAGES FOLLOW.]



                                       4

<PAGE>   5




         IN WITNESS WHEREOF, the parties hereto have caused this instrument to
be made, executed and delivered by their duly authorized officers as of the day
and year first above written.

                                            BORROWER:

                                            MEDICAL DEVICE MANUFACTURING, INC.

                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------

                                            AGENT:


                                            BANK OF AMERICA, N.A.

                                            By: /s/ JANE JARRETT
                                               ---------------------------------
                                            Name: Jane Jarrett
                                                 -------------------------------
                                            Title: Principal
                                                  ------------------------------

                       AMENDMENT NO. 1 TO CREDIT AGREEMENT
                            SIGNATURE PAGE OF 1 OF 3

<PAGE>   6



                                            LENDERS:

                                            BANK OF AMERICA, N.A.

                                            By: /s/ JANE JARRETT
                                               ---------------------------------
                                            Name: Jane Jarrett
                                                 -------------------------------
                                            Title: Principal
                                                  ------------------------------


                                            FLEET NATIONAL BANK

                                            By: /s/ LINDA ALTO
                                               ---------------------------------
                                            Name: Linda Alto
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                                            DRESDNER BANK AG, NEW YORK BRANCH
                                            AND GRAND CAYMAN BRANCH

                                            By: /s/ JOHN M. BLAND
                                               ---------------------------------
                                            Name: John M. Bland
                                                 -------------------------------
                                            Title: Senior Vice President
                                                  ------------------------------

                                            By: /s/ TERRENCE WARD
                                               ---------------------------------
                                            Name: Terrence Ward
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                                            GUARANTORS:


                                            MDMI HOLDINGS, INC.


                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                                            G&D, INC.


                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                       AMENDMENT NO. 1 TO CREDIT AGREEMENT
                            SIGNATURE PAGE OF 2 OF 3

<PAGE>   7

                                            MEDICAL ENGINEERING RESOURCES, LTD.


                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                                            NOBLE-MET, LTD.


                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                                            UTI CORPORATION


                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------



                                            SPECTRUM MANUFACTURING, INC.


                                            By: /s/ STEVEN D. NEUMAN
                                               ---------------------------------
                                            Name: Steven D. Neuman
                                                 -------------------------------
                                            Title: Vice President
                                                  ------------------------------


                       AMENDMENT NO. 1 TO CREDIT AGREEMENT
                            SIGNATURE PAGE OF 3 OF 3