① Coarse grinding: Require abrasive knife to eat a deep, high grinding efficiency, grinding rough, grinding the surface is more rough, the main removal of the product in the front of the process of cutting marks and the smoothness of the product, molding surface grinding in place;
② Semi-fine grinding: The coarse grinding traces will be cleared to form a new finer grain, the product processing surface is flat and smooth;
③ Fine grinding: Fine grinding of the product patterns, particles, color has been clearly displayed, the surface is delicate, smooth, began to have a faint gloss;
④ Fine grinding: After processing the product, no visible traces of the naked eye. The surface is more and more smooth, gloss about 40 about;
⑤ Polishing: The surface is bright as a mirror, with a certain degree of specular gloss (85 degrees above).