VCOIL Plug Gauge (GO) - UNF (STI) - Heli Coil Gauge - Right Hand - 3B - 1.3/8 x 12 FHH while the 6 mm shank

while the 6 mm shank provides compatibility with a wide range of milling machines

Right-hand thread compatibility: Designed for standard right-hand threaded holes

Ideal for hobbyists and professionals alike

Left‑hand spiral flute with right‑hand cutting: Efficient chip evacuation and a smooth finish

and metalworking

VCOIL Plug Gauge (GO) - UNF (STI) - Heli Coil Gauge - Right Hand - 3B - 1.3/8 x 12 FHH while the 6 mm shankPrecise GO plug gauge for UNF (STI) right hand threads, purpose built for Helicoil insert applications. Ideal for workshop and quality control environments that strictly follow ANSI ASME thread standards. Gauge Type: GO thread plug gauge used to verify that the thread cut in a part will screw in by hand without excessive force. Thread System: UNF (STI) Right Hand Thread Size: 1. 3 8 x 12 UNF Size Class: 3B Calibration & Standards: Manufactured to ANSI