Hole cutter

A hole cutter having a cylindrical wall and a ring-shaped end surface, said end surface having a first cutting edge and a second cutting edge alternating along a periphery of said end surface, wherein said cutter rotates to form a hole in a workpiece and removes cutting chips, said cutter comprising:

• said first cutting edge having a pair of first side sections and a first middle section that separates said first side sections, wherein said first middle section projects downward from at least one of said first side sections;
• said second cutting edge having a pair of second side sections and a second middle section that separates said second side sections, wherein said second middle section projects downward from said second side sections;
• said second cutting edge having means for cutting the workpiece with the cutting chips being removed therefrom in a strip-like shape;
• and
• a plurality of third cutting teeth, each of said third cutting teeth being located next to one of said second cutting teeth and between adjacent ones of said first cutting teeth.

A hole cutter having a cylindrical wall and an end for forming a hole in a workpiece, said cutter comprising:

• a plurality of first cutting teeth peripherally arranged on the end of the cutter, adjacent ones of said cutting teeth being separated from one another;
• a plurality of second cutting teeth, each provided between said adjacent first cutting teeth;
• and
• a plurality of third cutting teeth, each of said third cutting teeth being located next to one of said second cutting teeth and between adjacent ones of said first cutting teeth.