RNA6903-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 RNA6903-XL model number is decoded

envelope 22×30×23 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 21.1 kN and C0 29 kN at the 22 mm seat; the C/C0 ratio of 0.73 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 5.2 kN, the limiting speed 20,000 r/min and the thermal reference speed 10,500 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 0.96 kN/mm and per millimetre of width 0.92 kN/mm — the reason 23 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 42.4 g, just 0.06 g per mm² of projected 30×23 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 22 mm bore the 23 mm width and 21.1 kN C rating suit high-cycle industrial machinery rather than instrument duty The hardness requirement is unforgiving: below about 58 HRC the 22 mm journal brinels under the 29 kN static rating, and roughness above raceway finish accelerates roller wear Omitting the inner ring frees radial space — at a 22 mm shaft the outer diameter is only 30 mm and the width 23 mm, yet C is 21.1 kN As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 5.2 kN Cur value. Typical applications include copying and printing machine mechanisms, gearbox selector and change linkages and hydraulic and pneumatic pump eccentrics, where the 30 mm outside diameter and 21.1 kN dynamic rating match the duty. In copying and printing machine mechanisms the unit fits a compact 22 mm seat, and in gearbox selector and change linkages the 42.4 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for hydraulic and pneumatic pump eccentrics, relying on the 23 mm width and the published 29 kN static rating. Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately. On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.

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.
• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.