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 5960-00-279-3536
NSN 6145-00-681-1585
NSN 6320-00-218-6105
NSN 5920-01-594-6994
NSN 6105-01-338-4715
NSN 5998-01-258-9676
NSN 6650-01-052-7121
NSN 5895-01-318-5837
NSN 6650-00-896-4915
NSN 5895-01-611-3002
NSN 5925-00-044-5793
NSN 5996-01-601-4199