NK24-20-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 NK24-20-XL model number is decoded

envelope 24×32×20 mm: 24 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 4.0 mm radial section packed with small-diameter needle rollers C is 21.4 kN and C0 30.5 kN at the 24 mm seat; the C/C0 ratio of 0.70 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 32 mm outside diameter the fatigue load limit Cur is 5.4 kN, the limiting speed 18,500 r/min and the thermal reference speed 10,700 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 0.89 kN/mm and per millimetre of width 1.07 kN/mm — the reason 20 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 40 g, just 0.06 g per mm² of projected 32×20 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 24 mm bore the 20 mm width and 21.4 kN C rating suit high-cycle industrial machinery rather than instrument duty Omitting the inner ring frees radial space — at a 24 mm shaft the outer diameter is only 32 mm and the width 20 mm, yet C is 21.4 kN 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 24×32×20 mm envelope. Typical applications include motorcycle and light-vehicle transmissions, connecting-rod small ends and two-stroke and compressor piston pins, where the 32 mm outside diameter and 21.4 kN dynamic rating match the duty. In motorcycle and light-vehicle transmissions the unit fits a compact 24 mm seat, and in connecting-rod small ends the 40 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for two-stroke and compressor piston pins, relying on the 20 mm width and the published 30.5 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. Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.

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.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.