TSUCHIYA DIE (formerly Tsuchiya Manufacturing Facility) designed core mold equipment

References on the EI Core


 This in an Outline to the cornerstone

 of Japan's EI core hystory.

◇ Various dimensions of the EI core


 We listed the Core size both in Millimeters, used in 

 Japan, and Inches, used overseas.

 Please freely save & print the drawings and other               material,using it as you please.


 Please contact us if you are looking for core products.

 We can provide information on core manufacturers both 

 in Japan and other countries.

 We are proposing to transformer 

 designers a new core shape. 


◇ Japanese Industrial Standards JIS C 6431 [Dimensions of transformer core laminate for communication equipment]


(Public announcement on July 4, 1957 ~ abolition until November 1, 1964)

This standard was abolished in 1962. We made a copy of the original as reference material.

Although the layout such as the number of lines has been changed, the contents of the description are same to the original.