Inner rings are used wherever needle roller bearings are used but the shaft cannot be hardened or ground. They serve as a wear-resistant raceway for needle roller and cage assemblies, needle roller sleeves or needle roller bushings and ensure precise and long-lasting operation.
The inner rings of the IR series are the standard design. They are made of hardened and ground roller bearing steel, have a finely machined raceway with chamfers on both sides and are also available with a lubrication hole in selected sizes (designation IS1).