RNA4838-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 RNA4838-XL model number is decoded

envelope 210×240×50 mm: 210 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 15.0 mm radial section packed with small-diameter needle rollers C is 255 kN and C0 690 kN at the 210 mm seat; the C/C0 ratio of 0.37 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 240 mm outside diameter the fatigue load limit Cur is 102 kN, the limiting speed 2,250 r/min and the thermal reference speed 1,360 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 1.21 kN/mm and per millimetre of width 5.10 kN/mm — the reason 50 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 3.21 kg (3210 g), just 0.27 g per mm² of projected 240×50 mm envelope, which keeps unbalanced forces low in fast-actuating linkages 210 mm bore, 240 mm outside diameter: at this size the 690 kN C0 rating and rigid full-complement pack replace multi-bearing arrangements in compact heavy-duty designs Omitting the inner ring frees radial space — at a 210 mm shaft the outer diameter is only 240 mm and the width 50 mm, yet C is 255 kN -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 255 kN C rating and longer nominal life come without an envelope change. Typical applications include connecting-rod small ends, textile machine heald and cam shafts and motorcycle and light-vehicle transmissions, where the 240 mm outside diameter and 255 kN dynamic rating match the duty. In connecting-rod small ends the unit fits a compact 210 mm seat, and in textile machine heald and cam shafts the 3.21 kg mass is part of the rotor inertia calculation. Designers also specify it for motorcycle and light-vehicle transmissions, relying on the 50 mm width and the published 690 kN static rating. 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. Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.