Exhibit 21.1

Subsidiary	Registered in	Acquired
A. M. Castle & Co. (Canada) Inc.	Ontario	July 31, 1990
Total Plastics, Inc.	Michigan	January 2, 1996
Oliver Steel Plate Co.	Delaware	July 15, 1998
Paramont Machine Company, LLC	Delaware	April 1, 1999
Advanced Fabricating Technology LLC.	Delaware	May 1, 2000
Keystone Tube Company, LLC*	Delaware	October 1, 2000
Castle Metals de Mexico S.A. de C.V.	Mexico	February 27, 2004
Transtar Inventory Corp.	Delaware	September 5, 2006
Transtar Metals Corp.	Delaware	September 5, 2006
Transtar Metals Limited	United Kingdom	September 5, 2006
Transtar Metals (France)	France	September 5, 2006
A. M. Castle & Co. (Singapore) Pte. Ltd.	Singapore	October 13, 2006
A.M. Castle Metal Materials (Shanghai) Co., Ltd.	Pu Dong Province, Peoples Republic of China	November 22, 2007
A. M. Castle Metals UK, Limited*	United Kingdom	October 11, 2007
Castle Metals UK Limited	United Kingdom	January 2, 2008
Tube Supply, LLC	Texas	December 15, 2011
Tube Supply Canada ULC	Alberta	December 15, 2011

* Subsidiary was not acquired.

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