RNA4918-XL bearing: complete specifications & equivalents

Specification table

Source: catalog reference (HR1 2026-09-25) · extracted 2026-09-30

Parameters extracted from the official FAG Rolling Bearings catalogue (HR1 2026-09-25); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the RNA4918-XL model number is decoded

envelope 105×125×35 mm: 105 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 10.0 mm radial section packed with small-diameter needle rollers C is 129 kN and C0 250 kN at the 105 mm seat; the C/C0 ratio of 0.52 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 125 mm outside diameter the fatigue load limit Cur is 44.5 kN, the limiting speed 4,400 r/min and the thermal reference speed 2,650 r/min; for small needle bearings the reference speed can exceed the kinematic limit, so the lower of the two governs the application dynamic capacity per millimetre of bore is 1.23 kN/mm and per millimetre of width 3.69 kN/mm — the reason 35 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 745 g, just 0.17 g per mm² of projected 125×35 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 105 mm bore belongs to the large band, where HR1 full-complement and track-roller designs deliver their highest kilonewton ratings in slow, heavily loaded machinery With Cur 44.5 kN and a 4,400 r/min limiting speed the unit suits pivots, rocker arms, pumps and compact gear trains running on hardened pins This bearing accepts axial displacement between shaft and housing because the rollers rotate on the free journal; it locates nothing axially and must be flanked by guide faces The -XL suffix is the Schaeffler X-life mark: interchangeable envelope with the basic bearing, but higher load capacity and lower running temperature at the 4,400 r/min limit. Typical applications include planetary gear bearings, small electric motor accessory drives and gearbox selector and change linkages, where the 125 mm outside diameter and 129 kN dynamic rating match the duty. In planetary gear bearings the unit fits a compact 105 mm seat, and in small electric motor accessory drives the 745 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for gearbox selector and change linkages, relying on the 35 mm width and the published 250 kN static rating. On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions. Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• Do not press an RNA/NK assembly in through the outer ring when mounting it on a shaft, and vice versa — rolling forces through the wrong ring bruises the raceways.