The dimensional and running accuracy of rolling bearings has been standardized internationally. In addition to the Normal tolerances the ISO standards also cover closer tolerances, e.g.
- tolerance class 6 which corresponds to SKF tolerance class P6
- tolerance class 5 which corresponds to SKF tolerance class P5.
For special applications, such as machine tool spindles, SKF also manufactures bearings with higher accuracy, e.g. to tolerance classes P4, P4A, P7, PA9A, P9, SP, SPC and UP.
Tolerance information about each bearing type is contained in the introductory texts to the various product sections under the heading "Tolerances". Bearings with higher accuracy than Normal are identified by a designation suffix for the tolerance class, see section Supplementary designations - Suffixes.
The actual tolerances are provided in the tables referenced in the following.
Metric radial bearings (except tapered roller bearings)
Inch radial bearings (except tapered roller bearings)
Metric tapered roller bearings
CLN (ISO class 6X)
Inch tapered roller bearings
Normal, CL2, CL3, CL0
Metric thrust bearings
Normal, P6, P5, P4
Tapered bores with taper 1:12
Normal, P6, P5
Tapered bores with taper 1:30