from Paul N. Gardner Co. Inc.
Plastic industrial drums with coarse female bung threads can now accept equipment designed for mounting in 2-inch NPT bung holes. DRUM-MATES(r) ThreadConverters(tm) can be used in any container with Buttress or Mauser coarse bung threads. The hex head, bung-hole adapters tightly screw into the coarse thread and convert it to 2-inch NPT.