Sec Form 4 Filing - Heideman Robert J @ SMITH A O CORP - 2013-07-26

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Heideman Robert J 2. Issuer Name and Ticker or Trading Symbol SMITH A O CORP [ AOS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Senior VP & Chief Tech Officer (Last) (First) (Middle) A. O. SMITH CORPORATE TECHNOLOGY CENTER, 12100 WEST PARK PLACE 3. Date of Earliest Transaction (MM/DD/YY) 07/26/2013 (Street) MILWAUKEE, WI53224 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 07/26/2013 M 3,300 A $ 13.965 7,092 D Common Stock 07/26/2013 S 3,300 D $ 40.9724 3,792 ( 1 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Employee Stock Options (Right to Buy) $ 13.965 07/26/2013 M 3,300 ( 2 ) 02/08/2011 02/08/2020 Common Stock 3,300 $ 0 28,000 ( 3 ) D Restricted Stock Units $ 0 ( 4 ) ( 4 ) Common Stock 0 13,236 ( 4 ) D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Heideman Robert J A. O. SMITH CORPORATE TECHNOLOGY CENTER 12100 WEST PARK PLACE MILWAUKEE, WI53224 Senior VP & Chief Tech Officer Signatures James F. Stern, Attorney-in-Fact for Robert J. Heideman 07/29/2013 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On May 15, 2013, the common stock of A. O. Smith Corporation split 2-for-1, resulting in the reporting person's ownership of 1,896 additional shares of common stock. ( 2 )The employee stock options were granted on 02/08/2010, under the A. O. Smith Combined Incentive Compensation Plan, a transaction exempt under Rule 16b-3. ( 3 )On May 15, 2013, the common stock of A. O. Smith Corporation split 2-for-1, resulting in the reporting person's ownership of 15,650 additional employee stock options. ( 4 )On May 15, 2013, the common stock of A. O. Smith Corporation split 2-for-1, resulting in the reporting person's ownership of 6,610 additional restricted stock units. Restricted Stock Units awarded to Robert J. Heideman on 02/09/2009 and 02/08/2010, were deferred. These deferred Restricted Stock Units receive a quarterly dividend pursuant to a dividend reinvestment feature of the A. O. Smith Nonqualified Deferred Compensation Plan. The total amount of dividends received were 16 Restricted Stock Units.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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