Abstract: An improved device and method for use in machining a workpiece, which includes a tool body with a machining tool having two machining surface, wherein one of the machining surfaces is being selectively movable between a retracted position and an extended position. A supporting mechanism is sized and configured to substantially restrict movement of the machining tool relative to the tool body while the one machining surface is positioned in the retracted position. Preferably, the supporting mechanism includes an interior surface having a frustoconical-shaped tapered configuration, and the reciprocable machining surface has an engageable surface sized and configured to be frictionally engaged against the interior surface. In a preferred embodiment, the interior surface has an angle relative to the longitudinal axis of the tool body from about 20 to about 50 degrees, and more preferably about 40 degrees.

Abstract: A unitary bore forming and threading tool for producing a variety threaded bores having chamfers and counterbores without a need for tool changes. The improved took preferably includes a shaft of predetermined axial length and having proximal and distal ends, a shank located adjacent the proximal end, a holemaking element located adjacent the distal end, and a threadmill portion located axially between the bit and the shank. The holemaking element further includes a chamfering surface and an end cutting surface. The disclosed tool and method enable creation of a variety of bores such as chamfers, counterbores, and threaded bores by producing bore portions of selectively determined distinct diameters by sequentially axially feeding the tool into the workpiece along distinct tool paths without changing tools. If desired, one or more of the bore portions can be threaded with the threadmill by moving the threadmill in a selectively determined helical or nonhelical path.