Limit number is h3; in accordance with us army drawing 11b5090651
An internal threading tool with longitudinally separated cutting edges designed to form specific threads.
Classification: Tools for tapping or threading, parts thereof, of base metal
NSN 5960-00-018-3477
NSN 5920-01-066-0805
NSN 5985-01-568-8030
NSN 6610-01-437-2506
NSN 6145-00-964-7466
NSN 5910-01-500-1977
NSN 5895-01-184-0758
NSN 5996-01-407-7374
NSN 6110-01-550-3708
NSN 5855-00-925-0114
NSN 4140-01-089-9088
NSN 5945-01-551-7889