Patent ID: 8839879

Claim:
An anvil assembly for a tool, the tool including a tool element for working on a workpiece, the anvil assembly comprising: an anvil including a body having a cylindrical outer periphery defining a longitudinal axis, a head formed on a distal end of the body, the head including a substantially planar distal end surface, at least two substantially planar surfaces upon which the tool element is supportable, a detent aperture extending through one of the substantially planar surfaces substantially transverse to the longitudinal axis, an arcuate surface contiguous with the substantially planar surfaces and proximate the cylindrical outer periphery, a corner disposed adjacent the substantially planar surfaces, a detent element located in the detent aperture; and a sleeve surrounding at least a portion of the outer periphery of the body, the sleeve having a distal end against which the tool element is abutted when the tool element is coupled to the head; wherein the corner, at a location on the head between the detent element and the substantially planar distal end surface, is defined by one of a radius and a taper for transferring stress surrounding the detent aperture toward the arcuate surface of the head.