The grain size of grinding wheel is determined according to the user's required finish. The general principle ofgrain size selection is as follows:
Coarse-grained grinding wheel is suitable for:
(1) the material is soft, the elongation is large and the ductile materials like soft iron and nonferrous metal are similar
(2) cutting with large amount of feed
(3) surface roughness requirements are not high grinding
(4) grinding large contact surface
Fine grain grinding wheel is suitable for:
(1) the material is hard and brittle, such as hard tool steel and glass
(2) applications requiring high surface roughness
(3) the application of grinding small contact surface
(4) workpiece with small tool radius or degree of isolation, such as thread tool grinding