A: 1. The dimensional requirements are different, and the dimensional deviations (inner diameter, outer diameter, ellipse, etc.) of products with high accuracy grades are smaller than those required by bearings with lower accuracy grades;

2. The required value of the bearing rotation accuracy is different. The rotation accuracy (internal radial runout, external radial runout, end face raceway runout, etc.) of products with high accuracy grades are stricter than those required by products with lower accuracy grades;

3. The requirements for surface shape and surface quality are different. For products with high accuracy grades, the surface shape and surface quality (surface roughness of raceways or channels, circular deviations, groove deviations, etc.) are lower than the accuracy grades. The required value of the product should be strict;

4. The materials of bearings with particularly high accuracy grades are more advantageous than those of products with general accuracy grades.