Patent ID: 6857832
Filing Date: 2005-02-22
Classification: B23B,Y10T

Abstract:
1. A drill bit for working metal, comprising a body having a center pilot tip at a front end thereof; the center tip transforming into two straight cutting edges at a base of the tip, each cutting edge extending toward an outer periphery of the body; the body defining a center axis of rotation passing through the cutting tip; each cutting edge forming a cutting angle relative to a reference plane extending perpendicularly to the axis, the cutting angles being equal and in the range of 1-20 degrees; the cutting tip including two tip edges converging forwardly from the base and forming a tip angle of 90±10°; the base, as viewed in a direction along the axis, having a length in the range of 23-45 percent of a maximum diameter of the front end of the drill; the tip forming a pilot point angle relative to the reference plane in the range of 90±2°.