DIN338 Twist Drill Bits HSS-R HSS-G HSS Cobalt
Short twist drills have a rank angle (sometimes referred to as angle of twist) of 27°, a point angle between 118° and 135° as well as a cylindrical shank. Type N is suitable for standard chipping materials. A distinction is made between roll forged and fully ground twist drills, depending on the production process.
When producing roll forged drills, the slugs are heated and formed into spiral coils. Fully ground drills get their spiral coil cut while being fully hardened. For a better distinc-tion between the diff erent types of twist drills, the following fi nishes are assigned to the diff erent drills:
|Point Angle||118° for HSS Rolled Drill Bits|
|135° Split Point for HSS-G/HSSE from 3.0mm|