Exhibit 21.1

Subsidiary	Jurisdiction of Incorporation	Ownership
Advanced Fabricating Technology, LLC***	Delaware	100%
A.M. Castle & Co. (Canada) Inc.	British Columbia	100%
A.M. Castle & Co. (Singapore) Pte. Ltd.	Singapore	100%
A.M. Castle Metal Materials (Shanghai) Co., Ltd.	Peoples Republic of China	100%
A.M. Castle Metals UK Limited	United Kingdom	100%
Castle Metals de Mexicali, S.A. de C.V.	Mexico	100%
Castle Metals de Mexico, S.A. de C.V.	Mexico	100%
Castle Metals France	France	100%
Castle Metals UK Limited	United Kingdom	100%
Depot Metal LLC*	Delaware	50%
E.Harding & Sons Limited	United Kingdom	100%
HY-Alloy Steels Company	Delaware	100%
Keystone Service, Inc.	Indiana	100%
Keystone Tube Company, LLC	Delaware	100%
K.K.S. (Stainless Steel) Co. Limited	United Kingdom	100%
LOKS Plasma Services Limited	United Kingdom	100%
Paramont Machine Company, LLC***	Delaware	100%
Tiernay Metals Limited	United Kingdom	100%
Total Plastics, Inc.	Michigan	100%
Transtar Metals Limited**	United Kingdom	100%

*	Entity was sold on August 22, 2016
**	Entity in liquidation
***	Entity was sold on March 15, 2016

E-1