RNA4909-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 RNA4909-XL model number is decoded

envelope 52×68×22 mm: 52 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 8.0 mm radial section packed with small-diameter needle rollers C is 51 kN and C0 73 kN at the 52 mm seat; the C/C0 ratio of 0.70 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 68 mm outside diameter the fatigue load limit Cur is 12.9 kN, the limiting speed 8,600 r/min and the thermal reference speed 4,900 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 0.98 kN/mm and per millimetre of width 2.32 kN/mm — the reason 22 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 182 g, just 0.12 g per mm² of projected 68×22 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 52 mm bore places this bearing in the medium band, where the 68 mm envelope already carries ratings in the tens of kilonewtons The hardness requirement is unforgiving: below about 58 HRC the 52 mm journal brinels under the 73 kN static rating, and roughness above raceway finish accelerates roller wear 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 8,600 r/min limit. Typical applications include copying and printing machine mechanisms, gearbox selector and change linkages and hydraulic and pneumatic pump eccentrics, where the 68 mm outside diameter and 51 kN dynamic rating match the duty. In copying and printing machine mechanisms the unit fits a compact 52 mm seat, and in gearbox selector and change linkages the 182 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for hydraulic and pneumatic pump eccentrics, relying on the 22 mm width and the published 73 kN static rating. Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone. 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

• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• 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.