There are two common types of shop made mandrels used for workpiece holding in the metalworking workshop, a parallel mandrel with a threaded hole in the end allowing the workpiece to be securely held with a screw, and a mandrel with a very slight taper where the workpiece is held purely by friction by being pressed onto the taper. The benefit of both is that if the mandrel remains in the chuck after machining it to be a close fit in the workpiece's bore then any subsequent machining of the workpiece will be concentric with the bore. The parallel mandrel however benefits from having a much more secure hold of the workpiece, particularly important if large diameters are being machined or intermittent cuts are taking place, as in the example that follows. Access to the sides of the part is limited though, due to the mandrel on one side and the securing screw on the other.
展开▼
