Patent ID: 9085033
Filing Date: 2015-07-21
Classification: B23B,Y10T

Abstract:
1. A drilling tool for drilling through-holes, the drilling tool comprising: a tool shank disposed about a center longitudinal axis, the tool shank including a holding region having a smooth clamping surface structured to be chucked in the chuck of a machine tool and an active region extending from the holding region; at least two partial cutting edges formed on an end face of the active region and running at right angles to the center longitudinal axis and form a drill main cutting edge; a clearance formed in the end face between the partial cutting edges, the clearance being recessed axially along the center longitudinal axis toward the tool shank; and a plurality of helical flutes formed in a circumferential surface of the active region, wherein the clearance comprises a concave shaped portion, and wherein each partial cutting edge merges smoothly into the clearance via a radius portion.