Description
Combination drill-tap with a 30° spiral flute, for Unified National Fine thread UNF 1/4″ with 28 TPI and Medium class of fit, dimensions according to DORMER-DIN standard with 6.3mm shank and 5.0mm square drive, HSS with steam tempered surface finish and 30° helix angle for 1.5xD through hole threading in free machining steel
