Internal Clearance

A bearing internal clearance is the total distance through a bearing can be moved in a radial direction (radial internal clearance) or an axial direction (axial internal clearance).

The internal clearance between a ball and raceway once mounted and at operational temperature, speed and load should be virtually zero. Therefore, it is important to always consider at least these three factors when determining the optimum clearance the bearing will need to reach a negligible distance between balls and race once at operational conditions.

Please see the table below for part number suffixes.

Suffix Radial internal clearance Used when…

C1

Less than C2

Precise control of radial run out and axial displacement with alternating load and no temperature gradient between inner race, outer race and mating components

C2

Less than Normal

CN

Normal

Used in applications with ambient or slight temperature differentials and ‘normal’ operating conditions

C3

Greater than Normal

Used for bearings with larger interference fits and/or temperature gradients between inner ring outer ring and mating components

C4

Greater than C3

C5

Greater than C4