NMTB 30 1-1/2-20 Boring Head tool holder

NMTB 30 Tool Holder

1-1/2 20TPI threaded head for mounting boring head
1/2-13 drawbar thread

Shank is smooth with no  nicks or burrs.
Drawbar threads in nicely with no resistance

If you happen upon a boring head with the wrong shank, you can use this holder to convert it over to your NMTB 30 spindle. The 1-1/2- 20 thread is standard across many manufacturers, including imports.