High speed drill reamer

摘要

A drill/reamer bit is described that is particularly suitable for high speed operation and which comprises a bit having a "split" pilot or drill portion with four facets and two cutting edges on each web and a "step" or reamer portion having two reliefs and one cutting edge associated with each web, the webs being formed by a pair of flutes angled at from approximately 81/2 DEG to approximately 23 DEG , the bit being formed primarily of fine grain tungsten carbide material, the drill portion having an included angle of approximately 118+/-2 degrees.