Twist drill bit

Abstract

A twist drill bit has first and second inclined cutting teeth. The first inclined cutting tooth includes at a first cutting edge a first guide projection formed at the periphery of the drill bit, and the second inclined cutting tooth includes at a second cutting edge a second guide projection formed at the periphery of the drill bit. The first and second guide projections have respective first and second guide faces that contact the work piece as the drill bit removes material from it.

1 . In a drill bit including an elongate body along which a longitudinal axis extends and in which multiple interlaced spiral flutes are formed about the longitudinal axis, the body terminating at a work engaging end having a periphery and an apex at which a tip is formed to lie on the longitudinal axis, the improvement comprising: 
 first and second inclined cutting teeth joined to form a tip;    the first inclined cutting tooth including a first guide projection formed at the periphery and a first cutting edge extending between the tip and the first guide projection, and the second inclined cutting tooth including a second guide projection formed at the periphery and a second cutting edge extending between the tip and the second guide projection; and    the first and second guide projections positioned on opposite sides of the periphery of the work engaging end, and the first and second guide projections having respective first and second guide faces that contact the work piece as the drill bit removes material from it.