SwissTech: 5/16"X24 UNF HSS-EV Blue Ring Spial Point/Gun Nose Tap - DIN 374 Spiral Point/Gun Nose - UNF HSS-EV Oxidised Finish UNF - Unified National Fine Bright Finish Taper lead to DIN form B (3.5 x P to 5.5 x P) Tapping tolerance to 2B M…View more