NA4844-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 NA4844-XL model number is decoded

envelope 220×270×50 mm: 220 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 25.0 mm radial section packed with small-diameter needle rollers C is 275 kN and C0 790 kN at the 220 mm seat; the C/C0 ratio of 0.35 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 270 mm outside diameter the fatigue load limit Cur is 112 kN, the limiting speed 1,980 r/min and the thermal reference speed 1,110 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 1.25 kN/mm and per millimetre of width 5.50 kN/mm — the reason 50 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 6.38 kg (6380 g), just 0.47 g per mm² of projected 270×50 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 220 mm bore this is among the largest catalogue sizes; the 1,980 r/min limiting speed confirms a slow-speed, extreme-load application such as a slewing or rolling-mill position Cur 112 kN, limiting speed 1,980 r/min, reference speed 1,110 r/min — the inner ring adds a few grams (total 6380 g) but removes the hardening requirement 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 1,980 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 270 mm outside diameter and 275 kN dynamic rating match the duty. In two-stroke and compressor piston pins the unit fits a compact 220 mm seat, and in motorcycle and light-vehicle transmissions the 6.38 kg mass is part of the rotor inertia calculation. Designers also specify it for rocker arms and valve trains, relying on the 50 mm width and the published 790 kN static rating. 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. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• 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.