Patent attributes
The invention relates to a twist drill, with an elongated drill body displaying a connecting end, a middle part, and a working end with a center point, in addition to at least two main cutting edges that run roughly transversely to the longitudinal axis of the drill body and lie opposite one another in relation to the longitudinal axis, where main cutting edges are each provided with a radially outer tip, which projects in feed direction x of twist drill, a helical chip removal flute follows on from each main cutting edge, center point displays at least two pilot cutting edges, and pilot cutting edges start from the free end of center point, run roughly transversely to the longitudinal axis of drill body and lie opposite one another in relation to the longitudinal axis. In order to achieve a drill hole with flawless, clean edges, pilot cutting edges are each be provided with a radially outer tip projecting in the feed direction of the twist drill, and a pilot chip removal flute follows on from each pilot cutting edge, transitioning into chip removal flute.
