The resin cylinder sand wheel is mainly used for processing the plane of the processed workpiece and for the coarse grinding of steel ball. Grinding wheel with large external diameter is mostly used for grinding plane on vertical flat grinder. Grinding wheel with smaller external diameter is used for grinding the spherical surface of bearing roller. The cup type grinding wheel is mainly used for cutter sharpening milling cutter, rymer, expanding drill, scraping out cutter, and scudding knife as well as for plane and internal grinding circle.