Bearing Tolerances

Tolerance classes and the corresponding values for radial bearings is specified in ISO 492 & DIN 620-2.  Tolerance classes and the corresponding values for thrust bearings is specified in ISO 199 & DIN 620-3.

Mainly there are three common classes for Ball Bearings and Roller Bearings

Tolerance ClassDescription
NormalMinimum standard for HBT’s Ball Bearings and Roller Bearings.
Class 6Tighter Tolerance than Normal
Class 5Tighter Tolerance than Class 6

Bearing Tolerances Symbols and Definations

SymbolsDefinations
dNominal bore diameter
ΔdmpDeviation of mean bore diameter in a single plane.
Δd1mpDeviation of mean large end diameter in tapered bore.
VDspVariation of a single bore diameter in a single plane
VDmpVariation of a mean bore diameter
DNominal Outside Diameter
ΔDmpDeviation of mean outside diameter in a single plane
VDspVariation of a single outside diameter in a single plane