SMITH A O CORP — Director's Dealing 2012

May 3, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: SMITH A O CORP (AOS)
CIK: 0000091142
Period of Report: 2012-05-02

Reporting Person: RETTLER STEVE W (Senior Vice President - CD)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-02	Common Stock	M	7200	$23.76	Acquired	25629	Direct
2012-05-02	Common Stock	S	2400	$47.80	Disposed	23229	Direct
2012-05-02	Common Stock	S	100	$47.81	Disposed	23129	Direct
2012-05-02	Common Stock	S	800	$48.05	Disposed	22329	Direct
2012-05-02	Common Stock	S	250	$48.057	Disposed	22079	Direct
2012-05-02	Common Stock	S	475	$48.06	Disposed	21604	Direct
2012-05-02	Common Stock	S	575	$48.07	Disposed	21029	Direct
2012-05-02	Common Stock	S	1349	$48.087	Disposed	19680	Direct
2012-05-02	Common Stock	S	851	$48.09	Disposed	18829	Direct
2012-05-02	Common Stock	S	100	$48.10	Disposed	18729	Direct
2012-05-02	Common Stock	S	100	$48.12	Disposed	18629	Direct
2012-05-02	Common Stock	S	200	$48.13	Disposed	18429	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-02	Employee Stock Options (Right to Buy)	$23.76	M	7200	Disposed	2018-02-11	Common Stock (7200)	Direct

Footnotes

F1: The employee stock options were granted on 02/11/2008 under the A. O. Smith Combined Incentive Compensation Plan, a transaction exempt under Rule 16b-3.