Hohlbohrer

摘要

An improved annular hole cutter is disclosed that has a plurality of alternately arranged first and second cutting teeth positioned at substantially equally spaced intervals about the distal end of the cutter body. All of the cutting teeth having angled bottom faces that are tapered at the same angle towards a radially inner side of the bottom faces. The first cutting teeth each have a substantially straight leading edge that includes an active cutting surface and an inactive surface. The second cutting teeth each have circumferentially stepped inner and outer cutting edges. The relative axial heights of the cutting teeth are adjusted so that the active cutting surfaces of the first cutting teeth are formed at the same axial height as their radially corresponding cutting edges of the second cutting teeth. At the same time, the inactive surface of the first cutting teeth are formed at a different axial height than their radially corresponding cutting edges of the second cutting teeth. This cutter arrangement produces both thin and thick chips that do not excessively entangle to improve cutting efficiency.