The shape of grinding wheel mainly includes flat grinding wheel, double-sided concave grinding wheel, double-bevel grinding wheel, cylindrical grinding wheel, dish-shaped grinding wheel, and bowl-shaped grinding wheel. According to the needs of machine tool structure and grinding processing, the grinding wheel is made into various shapes and sizes. Table 6 shows the shapes, sizes, codes and uses of several commonly used grinding wheels. The outer diameter of the grinding wheel should be selected as large as possible to improve the peripheral speed of the grinding wheel, which is beneficial to improve the grinding productivity and surface roughness. In addition, if the rigidity and power of the machine tool permit, if the grinding wheel with larger width is selected, the productivity and roughness can also be improved. However, when grinding materials with high thermal sensitivity, the width of the grinding wheel should be appropriately reduced to avoid burns and cracks on the surface of the workpiece.