Inner rings for needle roller bearings

An inner ring is a hardened, ground raceway that fits on the shaft and gives the needles a surface to roll on. You need one when the shaft lacks the hardness or finish a raceway requires, or when radial space is tight but load capacity has to stay high. It is also a way to restore the raceway on a worn shaft.

Inner rings are identified by three dimensions in millimeters: bore × outside diameter × width. SKF's IR 100X110X30 measures 100 × 110 × 30 mm; for NSK, FIR-354015 means 35 × 40 × 15 and FIR-404520 means 40 × 45 × 20. The ring's outside diameter is the raceway diameter, so it has to match the bore of the bearing or cage that runs on it.

They are common in transmissions, pumps, compressors, machine tools and lifting equipment. To choose a ring, define the shaft diameter, the width of the needle roller bearing and the lubrication. A ring slightly wider than the cage lets the needles shift without running off the raceway.

We carry NSK and SKF inner rings. Send the complete part number or the three dimensions by WhatsApp, together with the part number of the needle roller bearing or cage that runs on the ring, and we will quote it promptly.