Generally, in order to meet the needs of different users for bearings, the bearing accuracy provided by the manufacturer will be different. In order to standardize the accuracy level of bearings, they are generally divided according to dimensional accuracy and rotational accuracy.

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 diameter of roller group

3. Allowable limit value of chamfer size

4. Allowable variation of width

Rotational accuracy (items related to the runout of rotating body)

1. Allowable radial runout and axial runout of inner and outer rings

2. Allowable lateral runout of inner ring

3. Allowable variation of outer diameter surface inclination

4. Allowable variation of thrust bearing raceway thickness

5. Allowable deviation and allowable variation of tapered hole

Accuracy standard level

The accuracy level standards of bearings are 0, 6X, 6, 5, 4 and 2. The bearing accuracy increases from level 0. Level 0 is sufficient for general use, but when used in some conditions or occasions that require high precision, level 5 or higher accuracy is required.

Although the accuracy level is based on ISO standards, it is limited to China. Compared with foreign countries, the names and measurement standards of products in different countries are different.