EXHIBIT (21) SIGNIFICANT SUBSIDIARIES OF THE REGISTRANT Technitrol, Inc., which has no parent, has the following subsidiaries: Name Incorporation Percent Owned - ----------------------------------- ----------------------- ------------- John Chatillon & Sons, Inc. New York 100% Advanced Metallurgy, Inc. Pennsylvania 100% Technitrol International, Inc. Delaware 100% Chace Precision Metals, Inc. Delaware 100% Lloyd Instruments, Ltd. United Kingdom 100% Technitrol Investments, Inc. Delaware 100% Fil-Mag Taiwan Corporation Taiwan 100% Fil-Mag Philippines Corporation Philippines 100% Pulse Engineering, Inc. Delaware 100% Pulse Engineering Distribution, Ltd. Ireland 100% Pulse Electronics, Ltd. Hong Kong 100% Dongguan Pulse Electronics Co., Ltd. Peoples Republic of China 100% Page 37 of 38