Insize Digital Internal Caliper Gauge 5–15 mm Range Series 2121-15 50 mm Annular Cutter Extension Socket The Somta Series 581 is Dial Reading 0 40 SOMTA – Series 551 HSS UNF Thread Tap 1-1/8″ Intermediate – Short Hand Tap 16 ER AG55 BMA

The Somta Series 581 is a precision-ground HSS National Pipe Straight (NPS) taper tap designed for accurate and reliable parallel thread production in pipe fittings and fluid system components

Heat Resistant Up to 800°F: Withstands high temperatures

Please note this is a 3/8-16 BSW  thread

and tool durability

Insize Digital Internal Caliper Gauge 5–15 mm Range Series 2121 15 50 mm Annular Cutter Extension Socket The Somta Series 581 is Dial Reading 0 40 SOMTA – Series 551 HSS UNF Thread Tap 1 1 8″ Intermediate – Short Hand Tap 16 ER AG55 BMA The Somta Series 581 is a precision ground HSS National Pipe Straight (NPS) taper tap designed for accurate and reliable parallel thread production in pipe fittings and fluid system components Heat Resistant Up to 800°F: Withstands high temperatures