UNITED STATES
                          SECURITIES AND EXCHANGE COMMISSION
                                Washington, D.C 20549


                                     SCHEDULE 13G


                      Under the Securities Exchange Act of 1934


                                (Amendment No. __3__)*


                                A.O. Smith Corporation
          -----------------------------------------------------------------
                                   (Name of Issuer)

                                    Class B Common
          -----------------------------------------------------------------
                            (Title of Class of Securities)

                                       83186520
                          ----------------------------------
                                    (CUSIP Number)



     Check  the following box if a  fee is being paid  with this statement /__/.
     (A  fee is  not required  only if  the filing  person: (1)  has a  previous
     statement on file  reporting beneficial ownership of more than five percent
     of  the class  of securities  described in  Item l;  and  (2) has  filed no
     amendment  subsequent  thereto  reporting  beneficial  ownership   of  five
     percent or less of such class.) (See Rule 13d-7).

     *The remainder  of this  cover page  shall be  filled out  for a  reporting
     person's initial filing  on this form with respect  to the subject class of
     securities, and for  any subsequent amendment containing  information which
     would alter the disclosures provided in a prior cover page.

     The information required in  the remainder of this cover page shall  not be
     deemed  to be  "filed"  for the  purpose of  Section  18 of  the Securities
     Exchange  Act of  1934 ("Act") or  otherwise subject to  the liabilities of
     that section of  the Act but  shall be subject to  all other provisions  of
     the Act (however, see the Notes).








     SEC 1745 (2/92)              Page 1 of 8 pages





     CUSIP No.  83186520                 13G                   Page 2 of 8 Pages


      1       NAME OF REPORTING PERSON
              S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                      Mitchell Hutchins Asset Management Inc.
                      IRS ID No.:  13-2895752


      2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a) /__/
                               Joint Filing                      (b) /__/

      3       SEC USE ONLY

      4       CITIZENSHIP OR PLACE OF ORGANIZATION

                      Delaware

                               5       SOLE VOTING POWER
      NUMBER OF                                 None

       SHARES                  6       SHARED VOTING POWER
                                                326,700
     BENEFICIALLY

       OWNED BY                7       SOLE DISPOSITIVE POWER
                                                None
        EACH

      REPORTING

       PERSON                  8       SHARED DISPOSITIVE POWER
                                                326,700
        WITH


      9       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

              326,700  (Not  to  be  construed  as  an  admission  of Beneficial
              ownership)

     10       CHECK  BOX IF  THE AGGREGATE  AMOUNT IN  ROW (9)  EXCLUDES CERTAIN
              SHARES*


     11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

                                       1.56

     12       TYPE OF REPORTING PERSON*

                                       CO, BD, IA



     SEC 1745 (2/92)              Page 2 of 8 pages





     CUSIP No.  83186520                 13G                   Page 3 of 8 Pages


      1       NAME OF REPORTING PERSON
              S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                      Mitchell Hutchins Institutional Investors Inc.
                      IRS ID No.:  13-3180862


      2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a) /__/
                               Joint Filing                      (b) /__/

      3       SEC USE ONLY

      4       CITIZENSHIP OR PLACE OF ORGANIZATION

                      Delaware

                               5       SOLE VOTING POWER
      NUMBER OF                                 None

       SHARES                  6       SHARED VOTING POWER
                                                326,700
     BENEFICIALLY

       OWNED BY                7       SOLE DISPOSITIVE POWER
                                                None
        EACH

      REPORTING

       PERSON                  8       SHARED DISPOSITIVE POWER
                                                326,700
        WITH


      9       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

              326,700  (Not  to  be  construed  as  an  admission  of Beneficial
              ownership)

     10       CHECK  BOX IF  THE AGGREGATE  AMOUNT IN  ROW (9)  EXCLUDES CERTAIN
              SHARES*


     11       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

                                       1.56

     12       TYPE OF REPORTING PERSON*

                                       CO, IA



     SEC 1745 (2/92)              Page 3 of 8 pages





     CUSIP No.  83186520                 13G                   Page 4 of 8 Pages


     Item 1.
              (a)     Name of Issuer
                               A.O. Smith Corporation


              (b)     Address of Issuer's Principal Executive Offices

                               11270 W. Park Place
                               Milwaukee, WI 53244-3690

     Item 2.
              (a)     Name of Person Filing

                               Mitchell Hutchins Asset Management Inc.

              (b)     Address  of  Principal   Business  Office  or,  if   none,
                      Residence

                               1285 Avenue of the Americas
                               New York, NY  10019

              (c)     Citizenship

                               Delaware

              (d)     Title of Class of Securities

                               Class B Common

              (e)     CUSIP Number

                               83186520


     Item 3. If this  statement is filed pursuant to Rule 13d-1(b), or 13d-2(b),
     check whether the person filing is a:

              (a) /X/ Broker or Dealer registered under Section 15 of the Act

              (b) /_/ Bank as defined in section 3(a)(6) of the Act

              (c) /_/ Insurance Company  as defined in  section 3(a)(19) of  the
                      act

              (d) /_/ Investment Company  registered  under  section  8  of  the
                      Investment Company Act

              (e) /X/ Investment  Adviser registered  under  section 203  of the
                      Investment Advisers Act of 1940

              (f) /_/ Employee Benefit  Plan, Pension Fund  which is subject  to



     SEC 1745 (2/92)              Page 4 of 8 pages





     CUSIP No.  83186520                 13G                   Page 5 of 8 Pages


                      the provisions  of the Employee Retirement Income Security
                      Act of 1974 or Endowment Fund; see 240.13d-l(b)(l)(ii)(F)

              (g) /X/ Parent    Holding    Company,    in    accordance     with
                      240.13d-l(b)(ii)(G) (Note: See Item 7)

              (h) /_/ Group, in accordance with 240.13d-l(b)(l)(ii)(H)

     Item 4. Ownership

              Mitchell  Hutchins Asset  Management  Inc. ("MHAM")  and  Mitchell
     Hutchins  Institutional  Investors  Inc.  ("MHII")   each  disclaim  direct
     beneficial ownership of the securities  of A.O. Smith Corporation  reported
     herein, and the filing  of this Schedule 13G  shall not be construed  as an
     admission that these companies are the beneficial owners  of any A.O. Smith
     Corporation securities.

     (a)      Amount Beneficially Owned:

              See line item (9) of the cover pages.

     (b)      Percent of Class:

              See line item (11) of the cover pages.

     (c)      Number of shares as to which such person has:

              (i)     Sole Power to vote or to direct the vote:

                      See line item (5) of the cover pages.

              (ii)    Shared Power to vote or to direct the vote:

                      See line item (6) of the cover pages.

              (iii)   Sole Power to dispose or to direct the disposition of:

                      See line item (7) of the cover pages.

              (iv)    Shared Power to dispose or to direct the disposition of:

                      See line item (8) of the cover pages.

     Item 5. Ownership of Five Percent or Less of a Class

              If this  statement is being  filed to  report the fact  that as of
              the  date  hereof  the reporting  person  has  ceased  to  be  the
              beneficial  owner  of  more  than  5  percent  of  the  class   of
              securities, check the following (X).

     Item 6. Ownership of More than Five Percent on Behalf of Another Person.


     
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     CUSIP No.  83186520                 13G                   Page 6 of 8 Pages


              Various persons have the right to receive, or the power to  direct
              the receipt of, dividends or proceeds from the sale of  securities
              reported herein.

     Item 7. Identification and Classification of  the Subsidiary Which Acquired
     the Security Being Reported on By the Parent Holding Company

              See Exhibit A.

     Item 8. Identification and Classification of Members of the Group

              N/A

     Item 9. Notice of Dissolution of Group

              N/A

     Item 10. Certification

              By signing below I  certify that, to the best of my  knowledge and
              belief,  the securities  referred to  above were  acquired in  the
              ordinary course of business and were not acquired for the  purpose
              of and  do  not have  the effect  of changing  or influencing  the
              control of  the issuer of such securities and were not acquired in
              connection with  or as  a participant  in any  transaction  having
              such purposes or effect.

              Signature:

              After reasonable  inquiry and  to  the best  of my  knowledge  and
              belief,   I  certify  that  the  information  set  forth  in  this
              statement is true, complete and correct.


     Date:  February 13, 1996                   /s/ Michael Katz         *
                                                -------------------------
                                                Michael Katz
                                                Chief Financial Officer
                                                & Senior Vice President

     --------------------------
     *        Signature affixed  by Hiam Arfa  pursuant to a  power of  attorney
              dated  February  9,  1996   and  incorporated  by  reference  from
              Schedule 13G filed with the Securities and Exchange Commission  by
              Mitchell Hutchins  Asset Management  Inc. et  al. on February  13,
              1996 with respect to Flowers Industries, Inc.








     SEC 1745 (2/92)              Page 6 of 8 pages





     CUSIP No.  83186520                 13G                   Page 7 of 8 Pages



                              EXHIBIT A TO SCHEDULE 13G

                      ITEM 7 DISCLOSURE RESPECTING SUBSIDIARIES


              Mitchell Hutchins Institutional Investors Inc. ("MHII") is a
     wholly-owned subsidiary of Mitchell Hutchins Asset Management Inc.
     ("MHAM").  MHAM is a parent holding company as that term is defined by
     Rule 13d-1(b)(1)(ii)(G) of the Securities Exchange Act of 1934 (the
     "Act").  MHAM is a broker-dealer registered under Section 15 of the Act. 
     MHAM and MHII are investment advisers registered under section 203 of the
     Investment Advisers Act of 1940.

              MHAM and MHII are Delaware corporations whose business address is
              as follows:

                      1285 Avenue of the Americas
                      New York, NY  10019

              The companies filing this joint Schedule 13G report beneficial
     ownership of the Class B Common Stock of A.O. Smith Corporation in the
     following amounts:

     
Shares Owned Directly or through Shares Beneficially Owned Managed Accounts Company 1. Mitchell Hutchins Institutional Investors Inc. 326,700 326,700 2. Mitchell Hutchins Asset Management Inc. None 326,700
SEC 1745 (2/92) Page 7 of 8 pages CUSIP No. 83186520 13G Page 8 of 8 Pages JOINT FILING AGREEMENT Each of the undersigned persons hereby agrees and consents to this joint filing of Schedule 13G on such person s behalf, pursuant to section 13(d) and (g) of the Securities and Exchange Act of 1934, as amended, and the rules promulgated thereunder. Each of these persons is not responsible for the completeness or accuracy of the information concerning the other persons making this filing, unless such person knows or has reason to believe that such information is inaccurate. Dated: February 13, 1996
Mitchell Hutchins Asset Management Inc. Mitchell Hutchins Institutional Investors Inc. By: /s/Michael Katz * By: /s/Michael Katz * ------------------------- ---------------------- Michael Katz Michael Katz Chief Financial Officer Chief Financial Officer & Senior Vice President & Senior Vice President
-------------------------- * Signature affixed by Hiam Arfa pursuant to a power of attorney dated February 9, 1996 and incorporated by reference from Schedule 13G filed with the Securities and Exchange Commission by Mitchell Hutchins Asset Management Inc. et al. on February 13, 1996 with respect to Flowers Industries, Inc. SEC 1745 (2/92) Page 8 of 8 pages