RNA4903-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 RNA4903-XL model number is decoded

envelope 22×30×13 mm: 22 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 4.0 mm radial section packed with small-diameter needle rollers C is 12.4 kN and C0 14.6 kN at the 22 mm seat; the C/C0 ratio of 0.85 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 30 mm outside diameter the fatigue load limit Cur is 2.65 kN, the limiting speed 20,000 r/min and the thermal reference speed 10,900 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 0.56 kN/mm and per millimetre of width 0.95 kN/mm — the reason 13 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 22.2 g, just 0.06 g per mm² of projected 30×13 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 22 mm bore falls in the small band, the workhorse size for gearbox planetary positions, hydraulic pumps and general cam and linkage duty RNA4903-XL has no inner ring: the needle rollers run directly on the shaft journal, so the seat must be hardened (58–64 HRC) and ground to bearing raceway quality With Cur 2.65 kN and a 20,000 r/min limiting speed the unit suits pivots, rocker arms, pumps and compact gear trains running on hardened pins -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 12.4 kN C rating and longer nominal life come without an envelope change. Typical applications include rocker arms and valve trains, two-stroke and compressor piston pins and small electric motor accessory drives, where the 30 mm outside diameter and 12.4 kN dynamic rating match the duty. In rocker arms and valve trains the unit fits a compact 22 mm seat, and in two-stroke and compressor piston pins the 22.2 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for small electric motor accessory drives, relying on the 13 mm width and the published 14.6 kN static rating. Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.