Description
Combination drill-tap with a 30° spiral flute, for Unified National Fine thread UNF 1/2″ with 20 TPI and Medium class of fit, dimensions according to DORMER-DIN standard with 9.0mm shank and 7.1mm square drive, HSS with steam tempered surface finish and 30° helix angle for 1.5xD through hole threading in free machining steel
