The fitting surface of the shaft and housing may be finished by turning or fine boring when the bearing is used under general operating conditions. However, if the conditions require
minimum vibration and noise, or if the bearing is used under severe operating conditions, a ground finish is required.
Recommended accuracy and roughness of shafts and housings under general conditions are given in Table 14-1.
Table 14-1 Recommended accuracy and roughness of shafts and housings
| Item | Bearing class | Shaft | Housing bore |
|---|---|---|---|
| Roundness tolerance | classes 0, 6 | IT 3 - IT 4 | IT 4 - IT 5 |
| classes 5, 4 | IT 2 - IT 3 | IT 2 - IT 3 | |
| Cylindrical form tolerance | classes 0, 6 | IT 3 - IT 4 | IT 4 - IT 5 |
| classes 5, 4 | IT 2 - IT 3 | IT 2 - IT 3 | |
| Shoulder runout tolerance | classes 0, 6 | IT 3 | IT 3 - IT 4 |
| classes 5, 4 | IT 3 | IT 3 | |
| Roughness of fitting surfaces Ra | Small size bearings Large size bearings |
0.8 a 1.6 a |
1.6 a 3.2 a |
[Remark]
Refer to the figures listed in the attached table when the basic tolerance IT is required.
