BF Japan pliers

Apparently, the BF mark appears on various tools, including some Sears branded tools.  Some people suggest it stands for "Bulk Forged" but that really doesn't make any sense to me.  Anyway, it may have been a trademark used by Daido (founded in Tokyo in 1949) or Hozan (founded in Osaka in 1951) between 1969 and 1987.