Statement of Changes of Beneficial Ownership

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 OF SECURITIES
                                                                                  
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OMB Number: 3235-0287
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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(f) of the Investment Company Act of 1940
                      

1. Name and Address of Reporting Person *

Petrarca Mark A 		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 Vice Pres. - H.R. & P.A
(Last)          (First)          (Middle)

A. O. SMITH CORPORATION, 11270 WEST PARK PLACE 		3. Date of Earliest Transaction (MM/DD/YYYY)

7/20/2012
(Street)

MILWAUKEE, WI 53224
(City)        (State)        (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)

 
6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3) 		2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. 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   7/20/2012     M    22050   A $19.003   46172   D  
 
Common Stock   7/20/2012     S    5500   D $51.00   40672   D  
 
Common Stock   7/20/2012     S    4612   D $51.01   36060   D  
 
Common Stock   7/20/2012     S    2638   D $51.02   33422   D  
 
Common Stock   7/20/2012     S    1200   D $51.03   32222   D  
 
Common Stock   7/20/2012     S    1400   D $51.04   30822   D  
 
Common Stock   7/20/2012     S    1500   D $51.05   29322   D  
 
Common Stock   7/20/2012     S    700   D $51.06   28622   D  
 
Common Stock   7/20/2012     S    800   D $51.07   27822   D  
 
Common Stock   7/20/2012     S    100   D $51.08   27722   D  
 
Common Stock   7/20/2012     S    300   D $51.09   27422   D  
 
Common Stock   7/20/2012     S    100   D $51.0902   27322   D  
 
Common Stock   7/20/2012     S    200   D $51.10   27122   D  
 
Common Stock   7/20/2012     S    500   D $51.11   26622   D  
 
Common Stock   7/20/2012     S    300   D $51.12   26322   D  
 
Common Stock   7/20/2012     S    500   D $51.13   25822   D  
 
Common Stock   7/20/2012     S    100   D $51.14   25722   D  
 
Common Stock   7/20/2012     S    100   D $51.15   25622   D  
 
Common Stock   7/20/2012     S    100   D $51.18   25522   D  
 
Common Stock   7/20/2012     S    100   D $51.20   25422   D  
 
Common Stock   7/20/2012     S    300   D $51.21   25122   D  
 
Common Stock   7/20/2012     S    100   D $51.22   25022   D  
 
Common Stock   7/20/2012     S    200   D $51.24   24822   D  
 
Common Stock   7/20/2012     S    100   D $51.25   24722   D  
 
Common Stock   7/20/2012     S    100   D $51.31   24622   D  
 
Common Stock   7/20/2012     S    300   D $51.32   24322   D  
 
Common Stock   7/20/2012     S    200   D $51.33   24122   D  
 

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3) 		2. Conversion or Exercise Price of Derivative Security 3. Trans. Date 3A. Deemed Execution Date, if any 4. Trans. 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 7. Title and Amount of Securities Underlying Derivative Security
(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)   $19.003   7/20/2012     M         22050      (1) 2/9/2019   Common Stock   22050   $0   25300   D  
 

Explanation of Responses:
( 1)  The employee stock options wre granted on 02/09/2009 under the A. O. Smith Combined Incentive Compensation Plan, a transaction exempt under Rule 16b-3. The options become exerciable in three annual installments of 1/3 of the award starting on 02/09/2010.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
Petrarca Mark A
A. O. SMITH CORPORATION
11270 WEST PARK PLACE
MILWAUKEE, WI 53224

Senior Vice Pres. - H.R. & P.A

Signatures
James F. Stern, Attorney-in-Fact for Mark A. Petrarca 7/23/2012
** Signature of Reporting Person Date


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).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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