Abstract: An arrowhead, with a conoidal, dowel-like body and a point to provide sufficient penetration, has at least two pivotable sharp blades disposed aft of the point and symetrical about the body. The blades are triangular and are pivotably mounted to the body by their aft or rear angles and extend radially outward with one edge of the blade disposed against the body so that one of the acute angles of each blade points forward. In a preferred embodiment, each blade is slightly recessed within an axially parallel slot and the pivoting function is formed by a ring threaded through the respective aft angles of the blades. In turn, the ring is coaxially disposed around the body and suitably secure in place to prevent axial movement thereof.

Abstract: A cutting head adapted to be manually operated is positioned in relation to a worn bearing so that when the cutting head is rotated with pressure applied in the axial direction against the bearing. The head advances axially along the bearing while rotating and shaves or machines away the worn bearing surface so that a new sleeve may be fitted over the machined surface to provide a new bearing surface of the same diameter and position as the original bearing surface prior to its wearing. In one form the cutting tool is mounted on a spindle inserted into the hollow of the bearing for machining an exterior bearing surface. In another embodiment, the cutting head is on a shaft inserted through the bearing for centering the head. In still another embodiment the cutting head is arranged to advance within a hollow bearing to machine an inside bearing surface. In all embodiments provision is made for stopping the advancement of the cutting head when the proper axial length of bearing surface has been machined.