The National Union of Coal Mine Workers (Zentanko) was a trade union representing coal miners in Japan.
The union was founded in 1952, with the merger of a union which had split from the Japan Coal Miners' Union in 1949 with another dissident faction of that union.
[1] It was a founding affiliate of the Japanese Confederation of Labour, and by 1967, it had 31,799 members.
[2] It transferred to the Japanese Trade Union Confederation at the end of the 1980s, but lost members as the industry declined, and by 1996 was down to 1,750 members.
[3]