The accuracy of rolling bearings is divided into (mainly) dimensional accuracy and rotational accuracy. The accuracy level has been standardized and divided into five levels: P0, P6, P5, P4, and P2.

Accuracy increases sequentially from grade 0. For general use, grade 0 is sufficient, but when used in the conditions or occasions shown in Table 1, grade 5 or higher is required.

Although the above accuracy grades are based on ISO standard A, their names are different in national standards.

Table 2 lists the applicable accuracy grades for 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 Allowable error of outer complex circle diameter 3. Allowable limit value of chamfer size 4. Allowable variation of width

Rotation accuracy (items related to rotating body runout)

1, Allowable radial runout and axial runout of inner ring and outer ring 2. Allowable lateral runout of inner ring 3. Allowable variation of inclination of outer diameter surface Deviation and Allowable Variation