2015-08-21
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| Degree of accuracy | For gearing at d =100 mm, and at face width of | For toothed wheel hub and shaft shoulder at bore diameter (shaft diameter of) | |||
| < 55 | 55…110 | < 55 | 55…80 | > 80 | |
| 0.017 | 0.009 | 0.02 | 0.03 | 0.04 | |
| 0.021 | 0.011 | 0.02 | 0.03 | 0.04 | |
| 0.026 | 0.014 | 0.03 | 0.04 | 0.05 | |
| 0.034 | 0.018 | 0.03 | 0.04 | 0.05 |
As a base the shaft axis of rotation is used for surfaces where bearings are installed. In order to eliminate misalignments of elements that are installed on the shaft we will use as a base of all other shaft surfaces the surfaces where bearings are located.
Possible errors of a keyseat are non-parallelism and non-symmetry. Parallelism tolerance is marked as // and is equal to 0.6∙ tks ∙10-3, where tks is keyseat width tolerance range in micromeres (table 14.2). Symmetry tolerance is marked as 
and is 4∙ tks ∙10-3.
The next step is marking surfaces roughness.
Surface roughness may be evaluated by average deviation of profile Ra or height of profile irregularities Rz by ten points. Marking surface roughness by Ra is more preferable. The magnitude of surface roughness depends upon the surface treatment and the quality grade.
