Patent ID: 8105001

Claim:
A drill comprising: a tip portion comprising a tip; a longitudinal, rotational axis; a first flute and a second flute; a chisel edge being disposed at said tip of said drill; a first cutting tooth and a second cutting tooth being disposed between said flutes and being separated by said chisel edge; said first cutting tooth being asymmetrical with respect to said second cutting tooth; said first cutting tooth being of substantially similar size and comprising a substantially similar amount of material as said second cutting tooth; said first cutting tooth having a land which extends over approximately 90 degrees, and said second cutting tooth having a land which extends over approximately 90 degrees; said land of said first cutting tooth extends over a greater number of degrees than said land of said second cutting tooth; said first cutting tooth comprising: a first longitudinal cutting edge being disposed longitudinally along at least a portion of said first flute and being configured to make a rough cut in material in a rotational direction during operation; a first tip cutting edge being disposed on said tip portion of said drill and adjacent said first flute and being configured to first cut material during operation; a guide margin being disposed adjacent said first longitudinal cutting edge and being configured to follow said first longitudinal cutting edge during rotation; said guide margin having a substantially constant radius measured from the rotational axis; a support margin being configured to minimize vibration during cutting and being disposed to follow said guide margin during rotation and being disposed separate from and away from said guide margin; said support margin having a substantially constant radius being substantially the same as the radius of said guide margin; and a region having points with radii being less than the radius of said guide margin and said support margin being disposed between said guide margin and said support margin; and said second cutting tooth comprising: a second longitudinal cutting edge being disposed longitudinally along at least a portion of said second flute and being configured to cut material in the rotational direction during operation; a second tip cutting edge being disposed on said tip portion of said drill and adjacent said second flute and being configured to cut material; a clearance face being disposed adjacent said second longitudinal cutting edge and said second tip cutting edge and being configured to follow said second longitudinal cutting edge during rotation; said second longitudinal cutting edge and said clearance face being configured to make a smoothing and finishing cut to minimize roughness formed by a rough cut by said first longitudinal cutting edge; and points on said clearance face being disposed closer to the rotational axis than said second longitudinal cutting edge is disposed to the rotational axis.