This 1,1/2" pinchuck is ideal for initial mounting of bowl blanks particularly natural edge blanks or irregular pieces which present no flat surface to which a faceplate can be screwed. The first pinchucks used a small loose pin which rolled on a flat, milled on the side of the pinchuck surface. This much improved pinchuck uses a much larger pin which rolls on a cam shaped surface. The pin has a spring loaded ball at one end to keep it from falling off into the sawdust. The larger pin gives a much more secure grip
To attach it to the lathe a Masterchuck body is required which serves as an adaptor. You will also need a 1,1/2" sawtooth bit to drill the hole.