NA4902-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 NA4902-XL model number is decoded

envelope 15×28×13 mm: 15 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 6.5 mm radial section packed with small-diameter needle rollers C is 12 kN and C0 13.6 kN at the 15 mm seat; the C/C0 ratio of 0.88 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 28 mm outside diameter the fatigue load limit Cur is 2.47 kN, the limiting speed 21,100 r/min and the thermal reference speed 11,200 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 0.80 kN/mm and per millimetre of width 0.92 kN/mm — the reason 13 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 34 g, just 0.09 g per mm² of projected 28×13 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 15 mm bore the 13 mm width and 12 kN C rating suit high-cycle industrial machinery rather than instrument duty This is the choice for OEM production on soft shafts: machine the 15 mm seat to the recommended tolerance, fit the bearing, and let the inner ring provide the precision raceway Reading the NA49 prefix: machined-ring needle bearing with inner ring, one roller row, capable of pure radial load at 12 kN C 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 21,100 r/min limit. Typical applications include two-stroke and compressor piston pins, motorcycle and light-vehicle transmissions and rocker arms and valve trains, where the 28 mm outside diameter and 12 kN dynamic rating match the duty. In two-stroke and compressor piston pins the unit fits a compact 15 mm seat, and in motorcycle and light-vehicle transmissions the 34 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for rocker arms and valve trains, relying on the 13 mm width and the published 13.6 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.
• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.