Exhibit 4.6

                            Dated as of March 3, 1999

Teachers Insurance and Annuity
  Association of America
730 Third Avenue
New York, New York  10017

CIG & Co.
c/o CIGNA Investments, Inc.
900 Cottage Grove Road
Hartford, Connecticut  06152


Ladies and Gentlemen:

         Reference is made to those certain Note Purchase Agreements between
Hutchinson Technology Incorporated, a Minnesota corporation (the "Company"), and
each of Metropolitan Life Insurance Company and Metropolitan Insurance and
Annuity Company (each, a "Series A Purchaser" and collectively, the "Series A
Purchasers") and Teachers Insurance and Annuity Association of America (the
"Series B Purchaser"), each dated as of July 26, 1996 (each as heretofore
amended or otherwise modified, an "Agreement" and collectively, the
"Agreements"), providing for the issuance to the Series A Purchasers of the
senior notes of the Company in the aggregate original principal amount of
$25,000,000 (the "Series A Notes"), and the issuance to the Series B Purchaser
of a senior note of the Company in the original principal amount of $25,000,000
(the "Series B Note"). The addressees of this letter agreement (collectively,
the "Noteholders"), are the registered holders of 100% of the aggregate
outstanding principal amount of the Series A Notes and the Series B Note
(collectively, the "Notes") as reflected in the Note Register required to be
maintained by the Company pursuant to Section 10.1 of each of the Agreements,
and the Noteholders whose signatures are affixed below hold 100% of the
aggregate unpaid principal amount of the Notes outstanding as of the date
hereof.

         The Company has informed the Noteholders that it desires to amend the
Agreements in certain respects as of the date hereof, and the Noteholders have
agreed to such amendments as more fully described below in this letter agreement
("this Amendment").

         Now, therefore, the Company and the Noteholders (by their acceptance
hereof) hereby agree as follows:



         1.       AMENDMENTS.

         The Agreements will be amended as hereafter in this paragraph 1 set
forth, such amendments to become effective as provided in paragraph 3 hereof:

         (a)      Section 3.1(a) of the Agreements shall be amended by adding 
at the end thereof the following:

                  "If and whenever any Series A Note (but less than all of the
         Series A Notes) shall be prepaid pursuant to SECTION 3.8, the aggregate
         principal amount of the Series A Notes required to be prepaid on any
         date thereafter pursuant to the first sentence of this SECTION 3.1(a)
         shall be reduced in the same proportion as the aggregate principal
         amount of the Series A Notes outstanding immediately prior to said
         prepayment pursuant to SECTION 3.8 shall have been reduced by said
         prepayment. The Company will, in the event of any reduction pursuant to
         the immediately preceding sentence, promptly after the prepayment of
         Series A Notes giving rise to such reduction, furnish each holder of
         Notes with notice thereof setting forth the Company's calculation of
         the respective required prepayments and payment at final maturity of
         Series A Notes due thereafter pursuant to this SECTION 3.1(a) (giving
         effect to such reduction)."

         (b)      Section 3.1(b) of the Agreements shall be amended by adding 
at the end thereof the following:

                  "If and whenever any Series B Note (but less than all of the
         Series B Notes) shall be prepaid pursuant to SECTION 3.8, the aggregate
         principal amount of the Series B Notes required to be prepaid on any
         date thereafter pursuant to the first sentence of this SECTION 3.1(b)
         shall be reduced in the same proportion as the aggregate principal
         amount of the Series B Notes outstanding immediately prior to said
         prepayment pursuant to SECTION 3.8 shall have been reduced by said
         prepayment. The Company will, in the event of any reduction pursuant to
         the immediately preceding sentence, promptly after the prepayment of
         Series B Notes giving rise to such reduction, furnish each holder of
         Notes with notice thereof setting forth the Company's calculation of
         the respective required prepayments and payment at final maturity of
         Series B Notes due thereafter pursuant to this SECTION 3.1(b) (giving
         effect to such reduction)."

         (c)      Section 3.4 of the Agreements shall be amended to be and read 
in its entirety as follows:

                  "3.4. ALLOCATION OF PARTIAL PREPAYMENTS. In the case of each
         prepayment, whether required or optional, of less than the entire
         unpaid principal amount of all outstanding Notes of any series (other
         than any such prepayment pursuant to SECTION 3.8 in connection with the
         acceptance by one or more holders of Notes of such series of a
         Prepayment Offer referred to in SECTION 3.8), the principal amount of
         the Notes of such series so to be prepaid shall be allocated among all
         of the Notes of such


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         series at the time outstanding in proportion, as nearly as practicable,
         to the respective principal amounts thereof not theretofore prepaid.
         The amount of each such optional prepayment so allocated to the Notes
         of any series (other than pursuant to any such prepayment of Notes
         pursuant to SECTION 3.8) shall be credited against the remaining
         required prepayments and payment at final maturity of the Notes of such
         series in the inverse order of such required prepayments and payment at
         final maturity."

         (d)      Section 3.5 of the Agreements shall be amended to be and read 
in its entirety as follows:

                  "3.5. Maturity; Surrender, etc. In the case of each prepayment
         of Notes, the principal amount of each Note to be prepaid shall become
         due and payable on the date fixed for such prepayment in this Agreement
         (if such prepayment is to be made pursuant to SECTION 3.1) or in the
         notice of such prepayment pursuant to SECTION 3.3 (if such prepayment
         is to be made pursuant to SECTION 3.2) or in the Trust Agreement
         referred to in SECTION 3.8 (if such prepayment is to be made pursuant
         to SECTION 3.8), together with interest accrued on such principal
         amount to such date and the Makewhole Amount, if any, payable in
         connection with such prepayment. Any Note paid or prepaid in full shall
         thereafter be surrendered to the Company upon its written request
         therefor and cancelled and not reissued."

         (e)      Section 3 of the Agreements shall be further amended by adding
thereto, following Section 3.7 thereof, a new Section 3.8, which new Section
shall be and read in its entirety as follows:

                  "3.8. PREPAYMENT OF NOTES PURSUANT TO TRUST AGREEMENT. The
         Company shall be required to prepay Notes of each holder thereof which
         shall have given notice of such holder's acceptance of a Prepayment
         Offer made by the Company pursuant to (and as the term `Prepayment
         Offer' is defined in) Section 7.2(b) of that certain Trust Agreement,
         dated as of March 3, 1999 (as from time to time supplemented and
         amended and in effect, the "TRUST AGREEMENT"), between the Company and
         U.S. Bank Trust National Association, a national banking association,
         as trustee thereunder (together with its successors as such trustee,
         the "TRUSTEE"), for the equal and ratable benefit and security of the
         holders from time to time of the Notes and the holders from time to
         time of the Company's 1994 Notes referred to (and as the term `1994
         Notes' is defined) in the Trust Agreement, each such prepayment to be
         made at the price and on the date determined in accordance with, and
         otherwise as provided in, said Section 7.2(b) of the Trust Agreement.
         For the avoidance of doubt, no prepayment of Notes of any series
         pursuant to this SECTION 3.8 shall be deemed, for purposes of SECTION
         3.2 or SECTION 3.3, an optional prepayment pursuant to SECTION 3.2."

         2. REPRESENTATIONS AND WARRANTIES. The Company represents and warrants
and covenants to and for the benefit of the Noteholders as follows:


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         (a) The execution and delivery by the Company of this Amendment and the
performance by the Company of this Amendment and of the Agreements and the Notes
as amended hereby (i) have been duly authorized by all requisite corporate
action on the part of the Company (no action on the part of the shareholders of
the Company being required therefor), (ii) do not require the consent or
approval of (A) any Governmental Body, or (B) except as set forth below, any
other Person, and (iii) do not and will not, (A) violate (1) any provision of
any law, statute, rule or regulation or of the articles of incorporation or
by-laws of the Company, (2) any Order of any court, administrative body or
arbitrator or any rule, regulation or Order of any Governmental Body binding
upon the Company or any of its properties, or (3) any provision of any loan or
credit agreement, indenture, mortgage or other agreement or instrument to which
the Company is a party or by which it or any of its properties are or may be
bound, or (B) result in any breach of or constitute (alone or with notice or
lapse of time or both) a default under any such loan or credit agreement,
indenture, mortgage or other agreement or instrument.

         (b) This Amendment, and the Agreements as amended hereby, constitute
the legal, valid and binding obligations and agreements of the Company,
enforceable against the Company in accordance with their respective terms,
except as such enforcement may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium or similar laws or equitable principles relating to
or limiting creditors' rights generally.

         (c) As of the date hereof, and after giving effect to the amendments to
the Agreements effected by this Amendment, no Default or Event of Default has
occurred and is continuing under and within the meaning of the Agreements.

         3. EFFECTIVENESS. The amendments to the Agreements provided for in this
Amendment shall become effective upon the execution and delivery of counterparts
of this Amendment by the Company and the holders of 100% in aggregate principal
amount of Notes at the time outstanding (as provided in Section 12(a) of the
Agreements).

         4. MISCELLANEOUS. Except as specifically amended hereby, all terms and
provisions of each of the Agreements shall remain in full force and effect.
Without limiting the provisions of Section 15.1 of the Agreements, the Company
will pay all expenses incurred by each Noteholder in connection with this
Amendment. This Amendment may be executed in two or more counterparts, each of
which shall be deemed an original, but all of which taken together shall
constitute one and the same instrument. Capitalized terms used but not otherwise
defined in this Amendment shall have the meanings assigned to them by each of
the Agreements.


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         If you are in agreement with the foregoing, please so indicate by
executing the form of acknowledgment set forth below, whereupon this Amendment
shall become a binding agreement effective as of the date hereof.

                                               Very truly yours,

                                               HUTCHINSON TECHNOLOGY
                                                  INCORPORATED

                                               By   /s/ John A. Ingleman 
                                                 ----------------------------

                                                 Its  CFO
                                                    -------------------------

Agreed to and accepted as of
the date first above written.

TEACHERS INSURANCE AND ANNUITY
    ASSOCIATION OF AMERICA

By   /s/ Diane Hom                                   
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  Its   Director-Private Placements
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CIG & CO.

By   /s/ Edward Lewis                                
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  Its   Partner                                            
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