SwissTech: Swiss+Tech Blue Ring Spial Flute UNC (Unified Coase) Poduction Tap Bight Finish HSS-EV Spiral Flute (BLF) - UNC HSS-EV Oxidised Finish. For shorter blind holes. Taper lead to DIN form C (3 x P). Tapping tolerance to 6H. Manufactu…View more