Exhibit 21

Simpson Manufacturing Co., Inc. and Subsidiaries

List of Subsidiaries of Simpson Manufacturing Co., Inc.

At February 26, 2010

1.	Simpson Strong-Tie Company Inc., a California corporation
2.	Simpson Dura-Vent Company, Inc., a California corporation
3.	Simpson Strong-Tie International, Inc., a California corporation
4.	Simpson Strong-Tie Canada, Limited, a Canadian corporation
5.	Simpson Strong-Tie Europe EURL, a French corporation
6.	Simpson Strong-Tie, S.A.S., a French corporation
7.	Simpson Strong-Tie Japan, Inc., a California corporation
8.	Simpson Strong-Tie Australia, Inc., a California corporation
9.	Simpson Strong-Tie A/S, a Danish corporation
10.	Simpson Strong-Tie GmbH, a German corporation
11.	Simpson Strong-Tie Sp.z,o.o., a Polish corporation
12.	Simpson France SCI, a French corporation
13.	ATF GmbH, a Swiss corporation
14.	Simpson Strong-Tie Australia Pty Limited, an Australian corporation
15.	Simpson Strong-Tie Mexico, S. de R.L. de C.V., a Mexican corporation
16.	Simpson Manufacturing Cyprus Limited, a Cyprus limited liability company
17.	Simpson Strong-Tie Asia Limited, a Hong Kong company
18.	Simpson Strong-Tie Asia Holding Limited, a Hong Kong company
19.	Simpson Strong-Tie (Beijing) Company Limited, a Chinese company
20.	Simpson Strong-Tie (Zhangjiagang) Co., Ltd., a Chinese company
21.	Simpson Strong-Tie Ireland Limited, an Irish company
22.	Ahorn-Geräte & Werkzeuge Vertriebs GmbH, a German company
23.	Simpson Strong-Tie s.r.o., a Czech company
24.	Agence Internationale Commerciale Et Industrielle, S.A.S, a French corporation
25.	Societe Civile Immobiliere IMAG SCI, a French corporation