NA4901-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 NA4901-XL model number is decoded

envelope 12×24×13 mm: 12 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 6.0 mm radial section packed with small-diameter needle rollers C is 10.6 kN and C0 10.9 kN at the 12 mm seat; the C/C0 ratio of 0.97 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 24 mm outside diameter the fatigue load limit Cur is 1.97 kN, the limiting speed 23,200 r/min and the thermal reference speed 14,200 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 0.88 kN/mm and per millimetre of width 0.82 kN/mm — the reason 13 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 26 g, just 0.08 g per mm² of projected 24×13 mm envelope, which keeps unbalanced forces low in fast-actuating linkages 12 mm bore and only 26 g: the smallest sizes demand accurate shaft geometry, because the 6.0 mm section leaves no tolerance for a soft or tapered seat NA4901-XL is supplied with a machined inner ring, so it mounts on an ordinary turned and ground shaft of normal tolerance — hardening the journal is not required The inner ring is separable, so the outer-ring/roller assembly can be pressed into the housing first; the 10.9 kN C0 rating still assumes full rigid support under both rings The -XL suffix marks the X-life execution: refined raceway topography and upgraded materials lift the basic ratings versus the non-X-life bearing at the same 12×24×13 mm envelope. Typical applications include gearbox selector and change linkages, planetary gear bearings and copying and printing machine mechanisms, where the 24 mm outside diameter and 10.6 kN dynamic rating match the duty. In gearbox selector and change linkages the unit fits a compact 12 mm seat, and in planetary gear bearings the 26 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for copying and printing machine mechanisms, relying on the 13 mm width and the published 10.9 kN static rating. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations. 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

• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• Adding an IR inner ring changes the envelope logic: the same outer assembly then fits a smaller shaft — recheck bore, clearance and ratings when substituting.