The drill is given a tip and does not wander. Provides a round, straight hole with tight tolerances. The bits are ground to the same length so they work equally. The drill has a very long service life. It can be infinitely adjusted for all angles between 90° and 150°. The clearance angle can be set to the optimal angle for each drilling operation of 7°, 9°, 11° or 14°. The same drill holder can be used to grind drills between 3 and 22 mm. No replacement of sockets.