AMENDMENT NO. 1 TO AMENDED AND
                     RESTATED SECURITIES PURCHASE AGREEMENT


      This Amendment is made as of October 31, 1996, between Masco Corporation,
a Delaware corporation ("Masco"), and MascoTech, Inc., f/k/a Masco Industries,
Inc., a Delaware corporation (the "Company" or the "Issuer"), concerning that
certain Amended and Restated Securities Purchase Agreement (the "Securities
Purchase Agreement"), dated as of November 23, 1993, between Masco and the
Company.  All capitalized terms not otherwise defined in this Amendment shall
have the meanings given them in the Securities Purchase Agreement.

      A.    Masco holds 24,824,690 shares of the Common Stock, par value $1.00
per share, of the Company (the "Tech Common Stock");

      B.    Concurrently herewith, the Company has, among other things,
repurchased from Masco 17,000,000 shares of Tech Common Stock;

      C.    In connection therewith, Masco and the Company desire to amend
certain provisions of the Securities Purchase Agreement as set forth herein.

            IN CONSIDERATION of the mutual covenants and agreements contained in
this Amendment, the parties agree to amend the Securities Purchase Agreement as
follows:

      1.    Paragraph 1(b) is hereby amended to read in its entirety as follows:

            (b)   The Securities shall be issued in separate series with the
            interest rate on each such series being a rate per annum that is the
            higher of:  (I) 400 basis points over the average Treasury Rate (as
            hereinafter defined) for the week preceding the week in which the
            notice of purchase referred to in Paragraph 2 is given to Masco; or
            (ii) 75 basis points over the Comparable Debt Issuance Rate (as
            hereinafter defined).

                  "Treasury Rate" means the rate for noncallable direct
            obligations of the United States ("Treasury Notes") having a
            remaining maturity of five years, as published in the Federal
            Reserve Statistical Release H.15(519) (or any successor publication
            provided by the Board of Governors of the Federal Reserve System)
            under the heading "Treasury Constant Maturities."  If a rate for
            Treasury Notes having a remaining maturity of five years has not
            been so published or reported for the preceding week as provided
            above by 1:00 P.M., New York City time, on the day such notice is
            given to Masco, then the Treasury Rate shall be calculated by the
            Company and shall be a yield to maturity (expressed as a bond
            equivalent, on the basis of a year of 365 or 366 days, as
            applicable, and applied on a daily basis) of the arithmetic mean of
            the secondary market bid rates, as of approximately 1:30 P.M., New
            York City time, on the date of such notice, of three leading primary
            United 










            States government securities dealers selected by the Company for the
            purchase of Treasury Notes with a remaining maturity of five years.

            The "Comparable Debt Issuance Rate" means a per annum rate of
            interest determined as follows:

                  Each of the Company and Masco shall select an investment
                  banker within 3  business days from the date the notice of
                  purchase referred to in Paragraph 2 is given to Masco, and
                  those two investment bankers shall have 3 business  days to
                  select a third investment banker.  Each of the three
                  investment bankers shall have qualifications with respect to
                  the sale of debt instruments of manufacturing and industrial
                  companies.  Each of the three investment bankers shall have 3
                  business days to determine, in its good faith opinion, the per
                  annum rate of interest that the Company would be required to
                  pay if it were to issue the relevant series of Securities to
                  third party investors in a transaction negotiated at
                  arms'-length and priced as of the date the notice of purchase
                  referred to in Paragraph 2 is given to Masco, and each banker
                  shall set forth its conclusion in a letter addressed to each
                  of Masco and the Company and delivered to each of them by
                  12:00 noon EST on the 10th day from the date of the notice of
                  purchase given to Masco.  The arithmetic mean of the interest
                  rates determined by each of the three investment bankers shall
                  be the Comparable Debt Issuance Rate.

      2.    Paragraph 2(a) is hereby amended to read in its entirety as follows:

            (a)   Subject to the terms and conditions set forth herein, Masco
            agrees to purchase, at par, at any time or from time to time on or
            before March 31, 2002, upon the Company's written notice, up to $200
            million aggregate principal amount of Securities (the "Commitment").
            The Company's written notice shall specify the principal amount of
            Securities that Masco is required to purchase (which for each
            respective issuance of Securities shall be $10 million or any larger
            multiple of $1,000,000).  The interest rate for such Securities
            shall be determined in accordance with the provisions of Paragraph
            1(b).

      3.    The first sentence of Paragraph 3(a) is hereby amended to read in
its entirety as follows:

            (a)   Any closing of a sale of Securities to Masco hereunder shall
            occur at Masco's offices on the 10th Business Day (as hereinafter
            defined) after the Company gives Masco the written notice referred
            to in Paragraph 2.






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      4.    Section 5.2(b) of the Form of Subordinated Note attached as Exhibit
A to the Securities Purchase Agreement is hereby amended to read in its entirety
as follows:

            (b)   The holder's right to tender under clause (a) above shall be
            triggered upon the occurrence of either of the following events:

                  (I)   Any person or group (an "other entity"), within the
                  meaning of Section 13 (d) (3) of the Securities Exchange Act
                  of 1934, shall attain beneficial ownership, within the meaning
                  of Rule 13d-3 adopted under the Securities Exchange Act of
                  1934, or at least 50% of the voting power for election of the
                  Directors of the Issuer, or,

                  (ii)  The Issuer, directly or indirectly, consolidates or
                  merges with any other entity or sells or leases its properties
                  and assets substantially as an entirety to any other entity,
                  provided that this clause shall not apply to a transaction in
                  which the Company is the surviving company in any merger or
                  consolidation and in which the stock issued in such a
                  transaction is less than 40% of the common stock of the
                  Company issued and outstanding after the transaction.

      5.    A new Section 2 (c) is hereby added to read in its entirety as
follows:

            (c)   The Commitment shall terminate upon the occurrence of either
            of the following events:

                  (i)   Any person or group (an "other entity"), within the
                  meaning of Section 13 (d) (3) of the Securities Exchange Act
                  of 1934, shall attain beneficial ownership, within the meaning
                  of Rule 13d-3 adopted under the Securities Exchange Act of
                  1934, or at least 50% of the voting power for election of the
                  Directors of the Issuer, or,

                  (ii)  The Issuer, directly or indirectly, consolidates or
                  merges with any other entity or sells or leases its properties
                  and assets substantially as an entirety to any other entity,
                  provided that this clause shall not apply to a transaction in
                  which the Company is the surviving company in any merger or
                  consolidation and in which the stock issued in such a
                  transaction is less than 40% of the common stock of the
                  Company issued and outstanding after the transaction.
            
      6.    All other terms and conditions of the Securities Purchase Agreement
are hereby ratified and confirmed and remain in full force and effect.






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            IN WITNESS WHEREOF, the parties have duly executed and delivered
this Amendment as of the date first above written.



                                    MASCO CORPORATION



                                    By:/s/ John R. Leekley
                                    Name:  John R. Leekley
                                    Title: Senior Vice President and
                                              General Counsel


                                    MASCOTECH, INC.



                                    By: /s/ Timothy Wadhams
                                    Name:  Timothy Wadhams
                                    Title: Vice President-Controller and
                                              Treasurer

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