Patent ID: 7201544

Claim:
A drill for producing a deep hole, comprising: a core having a distal end; a spiral cutting edge formed around the core and having an edge line, wherein a tip section of said spiral cutting edge is formed at the distal end of the core and the edge line at the tip section is depressed toward the core of the drill such that said core distal end is recessed relative to a circumferential portion of said edge line tip section and such that said spiral cutting edge tip section defines a distalmost end of said drill, said edge line defining two support points; and a guide section formed on the core, said guide section being provided on a heel side and on a same circumference as that on which the circumferential portion of the cutting edge tip section passes, and wherein said guide section defines two support points that cooperate with the support points provided by said edge line so that the drill provides a four point contact with a material to be drilled.