Lubrication grooves are a feature of all taps of M3.0 and over. Manufactured to DIN 371/376. | Fluteless – HSS-EV (TiN Coated) | For through and blind holes. | Taper lead to DIN form B | (3.5 x P to 5.5 x P). Tapping tolerance to 6H. | ISO Metric Coarse