Patent ID: 7520703
Filing Date: 2009-04-21
Classification: B23B,Y10T

Abstract:
1. An elongated drill bit with a longitudinal axis comprising: a shank at one end; a working end at one end; a flute portion between said shank and working end, said shank, working end and flute section continuous with one another; the working end comprises a pilot tip with a first cutting portion having a rake face and a second cutting portion axially spaced from said pilot tip first cutting portion, said second cutting portion at a terminus of said flute portion, said second cutting portion includes a pair of cutting edges on opposing sides of said pilot tip; said second cutting edge are on an angle of about 22° to about 27° from a line transverse to said longitudinal axis, said second cutting edge is formed at the junction of a rake face defined by a surface of said flute adjacent said cutting edge, and a primary clearance face, adjacent said second cutting edge, a secondary clearance face continuous with said primary clearance face, said rake face of said first cutting portion is co-planar with said secondary clearance face.