The Technique of Lapping
When lapping small batches, the workpieces are guided in so-called workholders. These are plastic, aluminum or steel plates that are the same size as the inside diameter of the conditioning ring, and are provided with openings slightly larger than the workpieces. They serve to hold the workpieces in a constant position, preventing them from mutual collision and yet allowing diagonal interchange. Depending on the weight and size of the parts, parallelism tolerances within 0.002 mm can be achieved in this way. It is advantageous to bond liners on the workholders in order to prevent the lapping agent from being wiped off by the workholders lying flat on the working plate.