Brazing Bend,Brazing Straight Coupling,Street Elbow M Profile Press Fittings Co., Ltd. , http://www.nspipefitting.com In the repair of mechanical manufacturing and length measuring instruments, manual grinding methods are often used to obtain higher precision flatness and surface roughness. I have learned in my work practice that grinding is high regardless of wet or dry grinding. In the precision plane, the planes processed by the flat plate or the grinder are convex, and it is difficult to achieve the ideal flatness requirement. The specific reasons are as follows: