SMITH A O CORP — Director's Dealing 2007

May 22, 2007

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: SMITH A O CORP (AOS)
CIK: 0000091142
Period of Report: 2007-05-21

Reporting Person: MASSA RONALD E (Executive Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2007-05-21	Common Stock	M	23400	$18.313	Acquired	51006	Direct
2007-05-21	Common Stock	M	26900	$26.88	Acquired	77906	Direct
2007-05-21	Common Stock	S	21801	$39.00	Disposed	56105	Direct
2007-05-21	Common Stock	S	399	$39.01	Disposed	55706	Direct
2007-05-21	Common Stock	S	3200	$39.02	Disposed	52506	Direct
2007-05-21	Common Stock	S	1500	$39.03	Disposed	51006	Direct
2007-05-21	Common Stock	S	100	$39.04	Disposed	50906	Direct
2007-05-21	Common Stock	S	900	$39.05	Disposed	50006	Direct
2007-05-21	Common Stock	S	400	$39.06	Disposed	49606	Direct
2007-05-21	Common Stock	S	200	$39.07	Disposed	49406	Direct
2007-05-21	Common Stock	S	3100	$39.08	Disposed	46306	Direct
2007-05-21	Common Stock	S	3800	$39.09	Disposed	42506	Direct
2007-05-21	Common Stock	S	100	$39.10	Disposed	42406	Direct
2007-05-21	Common Stock	S	900	$39.11	Disposed	41506	Direct
2007-05-21	Common Stock	S	400	$39.12	Disposed	41106	Direct
2007-05-21	Common Stock	S	1800	$39.13	Disposed	39306	Direct
2007-05-21	Common Stock	S	1498	$39.14	Disposed	37808	Direct
2007-05-21	Common Stock	S	602	$39.15	Disposed	37206	Direct
2007-05-21	Common Stock	S	1100	$39.16	Disposed	36106	Direct
2007-05-21	Common Stock	S	100	$39.17	Disposed	36006	Direct
2007-05-21	Common Stock	S	1400	$39.18	Disposed	34606	Direct
2007-05-21	Common Stock	S	600	$39.19	Disposed	34006	Direct
2007-05-21	Common Stock	S	1900	$39.20	Disposed	32106	Direct
2007-05-21	Common Stock	S	700	$39.21	Disposed	31406	Direct
2007-05-21	Common Stock	S	100	$39.24	Disposed	31306	Direct
2007-05-21	Common Stock	S	500	$39.25	Disposed	30806	Direct
2007-05-21	Common Stock	S	500	$39.26	Disposed	30306	Direct
2007-05-21	Common Stock	S	300	$39.27	Disposed	30006	Direct
2007-05-21	Common Stock	S	100	$39.30	Disposed	29906	Direct
2007-05-21	Common Stock	S	500	$39.31	Disposed	29406	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2007-05-21	Employee Stock Options (Right to Buy)	$18.313	M	23400	Disposed	2008-10-06	Common Stock (23400)	Direct
2007-05-21	Employee Stock Options (Right to Buy)	$26.88	M	26900	Disposed	2012-10-11	Common Stock (26900)	Direct

Footnotes

F1: Options were granted on 10/06/1998 under the A. O. Smith Corporation 1990 Long-Term Executive Incentive Compensation Plan, a Rule 16b-3 Plan.

F2: Options were granted on 10/11/2002 under the A. O. Smith Combined Executive Incentive Compensation Plan, a Rule 16b-3 Plan.