Currently, as never before, there is an ever-increasing demand for higher workpiece accuracies. An amount of workpieces can only be produced using the current machine parks after undergoing very exacting set-up procedures and thus long change-over times.
Together with the dead centre point of the external grinder the centre hole forms a plain bearing. For optimum results the taper of the centre hole must be round and co-axial with the centre hole at the other end of the workpiece.
After hardening the workpiece, its centre holes are neither round nor oval, are out of alignment, covered with scale and too rough. To obtain good results rapidly in circular grinding - essential for productivity - the centre hole must be ground by a Klein Centre Hole Grinder before they are mounted on the external grinder.