Bearing accuracy and grade

The accuracy of rolling bearings is divided into (mainly) dimensional accuracy and rotation accuracy. The accuracy grades have been standardized and are divided into five grades: P0, P6, P5, P4, and P2.
The accuracy is increased sequentially from level 0, which is sufficient for general purpose level 0, but when used in the conditions or occasions shown in Table 1, accuracy of level 5 or higher is required.
Although the above accuracy grades are based on ISO standards, their names differ in national standards.
Table 2 lists the applicable accuracy grades of various bearing types and the comparison between national standards.

Dimensional accuracy (items related to shaft and housing installation)
1. Allowable deviation of inner diameter, outer diameter, width and assembly width
2. The allowable deviation of the diameter of the inner circle and the outer circle of the roller group
3. Allowable limit value of chamfer size
4. Allowable variation of width

Rotation accuracy (items related to the beating of rotating body)
1. Allowable radial runout and axial runout of inner ring and outer ring
2. Allowable lateral runout of the inner ring
3. Allowable variation of the inclination of the outer diameter surface
4. Allowable variation of the thickness of the thrust bearing raceway
5. Allowable deviation and allowable variation of tapered hole