RNA6908-ZW-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 RNA6908-ZW-XL model number is decoded

envelope 48×62×40 mm: 48 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 7.0 mm radial section packed with small-diameter needle rollers C is 74 kN and C0 116 kN at the 48 mm seat; the C/C0 ratio of 0.64 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 62 mm outside diameter the fatigue load limit Cur is 19.8 kN, the limiting speed 9,200 r/min and the thermal reference speed 5,400 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 1.54 kN/mm and per millimetre of width 1.85 kN/mm — the reason 40 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 256 g, just 0.10 g per mm² of projected 62×40 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 48 mm bore places this bearing in the medium band, where the 62 mm envelope already carries ratings in the tens of kilonewtons Omitting the inner ring frees radial space — at a 48 mm shaft the outer diameter is only 62 mm and the width 40 mm, yet C is 74 kN With Cur 19.8 kN and a 9,200 r/min limiting speed the unit suits pivots, rocker arms, pumps and compact gear trains running on hardened pins As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 19.8 kN Cur value. -ZW is the double-row needle-cage code; the two rows run on the same races and keep the unit separable and interchangeable with the single-row mounting space. Typical applications include gearbox selector and change linkages, planetary gear bearings and copying and printing machine mechanisms, where the 62 mm outside diameter and 74 kN dynamic rating match the duty. In gearbox selector and change linkages the unit fits a compact 48 mm seat, and in planetary gear bearings the 256 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for copying and printing machine mechanisms, relying on the 40 mm width and the published 116 kN static rating. Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO. 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

• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• 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.