C2 Bearings ~ A Brief Explanation

Bearing internal clearance is defined as the total distance through which one bearing ring can be moved relative to the other in the radial direction (radial internal clearance) or in the axial direction (axial internal clearance).

It is necessary to distinguish between the internal clearance of a bearing before mounting and the internal clearance in a mounted bearing which has reached its operating temperature (operational clearance).

The initial internal clearance (before mounting) is greater than the operational clearance because different degrees of interference in the fits and differences in thermal expansion of the bearing rings and the associated components cause the rings to be expanded or compressed.

C2 Bearings Summary

  • The bore, diameter and width of C2 bearings are identical to the standard version.
  • C2 are exactly the same quality but have a different a purpose.
  • C2 bearings have less internal radial clearances.
  • They can feel tighter than normal bearings and will not cope with higher temperature applications.
  • Unless the bearing you are replacing specifically says C2 on it then you should not replace it with a C2 bearing.
  • A rule of thumb is to replace like for like, there is no advantage to a C2 bearing in place of a standard bearing.