RADIAL INTERNAL CLEARANCES

* The radial internal clearance of a ball bearing is measured two ways and defined as the space

that exists between the balls and the raceway when the rings are displaced according to

illustrations 1 and 2. One way to measure this is through radial play. Functionally, a bearings’

radial play is more critical.

1) Radial 2)

Play

Axial

Play

The other way to measure internal clearance is through axial play. Although the radial and axial play of a particular bearing are both functions of the bearings internal clearance, the actual value of these measurements are usually quite different. For example: the radial play of an R6-ZZ

bearing could have a radial play of .0002 and an axial play ten times greater or .002.

Radial play has become the standard purchasing specification when ordering ball bearings.

R.B.I. sales/engineering will help specify a bearing where the application requires a more specific

axial play.

In specifying a bearing for any application certain things should be kept in mind concerning the

internal clearance of the bearing. The contact angle of the bearing is directly related to the

radial play - the higher the radial play, the higher the contact angle will be.