Bearing accuracy and grade

The accuracy of rolling bearing is divided into (main) dimensional accuracy and rotation accuracy. The accuracy level has been standardized, divided into grade 0, grade 6X, grade 6, grade 5, grade 4, and grade 2.

Accuracy increases from level 0, which is sufficient for general use, but requires level 5 or higher when used in conditions or situations as shown in Table 1.

Although the above accuracy grade is based on ISO standards, but its name varies in national standards.

Table 2 lists the accuracy grades applicable to 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. Allowable deviation of inner and outer compound circle diameter of roller group.

3. Allowable limit value of chamfering size.

4. Allowable variation of width.

Rotation accuracy (items related to the jump of a rotating body)

1. Radial and axial runout of inner ring and outer ring are allowed.

2.the inner ring is allowed to run horizontally.

3. Allowable variation of inclination of outer diameter surface.

4. Allowable variation of raceway thickness of thrust bearing.

5. Allowable deviation and allowable variation of conical holes.