Bearing Mounting and Fitting: Tolerances and Interference Fits || Dynaroll

If an interference fit is desired, then the dimensions of these parts must be carefully controlled and the tolerances of the bearing bore and OD must be factored into a calculation of the maximum and minimum interference.

The following table shows recommended shaft and housing sizes and tolerances for different applications. It is assumed that bearings used are ABEC 5 tolerance (+0 to -0.0002 inch) for bore and OD. If a different grade of bearing is used, this will affect the recommended dimensions of the mating part.

    L = Loose fit T = Tight fit      d = Bearing bore from table      D = Bearing O.D. from table

1. The interference factor fp (above) will affect final radial play. This must always be taken into account in designing a press fit bearing to a specific radial play range.
2. Allow for relative thermal expansion in calculating final radial play (see table next page).
3. MC5 radial play bearing (0.0005 to 0.0008 in.) recommended for tight press fit.
4. Tight press NOT recommended for bearings with ring thickness < 0.030 in.
   

Bearing Mounting and Fitting, Page 4: Thermal Expansion