Inner rings are made from hardened rolling bearing steel and have precision machined or ground raceways.

They are used where:

• the shaft cannot be used as a raceway for needle roller and cage assemblies, drawn cup needle roller bearings with open ends, drawn cup needle roller bearings with closed end and needle roller bearings
• needle roller bearings must be combined with wider inner rings in order to allow larger axial displacements of the shaft in relation to the housing
• optimum running surfaces are required for seal lips.

Inner rings IR have a precision machined raceway.

Chamfers on the end faces allow easy insertion into the bearing and prevent damage to the seal lips of the bearing.

Inner rings are available with and without a lubrication hole. Rings with a lubrication hole have the suffix IS1.

Inner rings LR have a ground raceway. The end faces are turned and the edges are broken.

These rings have larger tolerances than the rings IR. They are thus suitable for applications that allow larger width tolerances and less demanding requirements for axial runout.

Inner rings are available as a special design with a machining allowance z on the raceway (suffix VGS). The size of the allowance is dependent on the raceway diameter, see table.

Suffixes for available designs: see table.