Sherline radius cutting attachment swings a tool through an arc to put a radius on the end of a part. The pivot points and tool position are adjustable, so it is capable of cutting either a concave or convex shape. It came about as a result of studying the method used to shape grinding wheels. The radius cutting attachment swings a tool through an arc to put a radius on the end of a part. The pivot points and tool position are adjustable, so it is capable of cutting either a concave or convex shape. It came about as a result of studying the method used to shape grinding wheels.