NKI20-20-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 NKI20-20-XL model number is decoded

envelope 20×32×20 mm: 20 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 21.4 kN and C0 30.5 kN at the 20 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 8.1 kN, the limiting speed 18,500 r/min and the thermal reference speed 9,900 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 1.07 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 61 g, just 0.10 g per mm² of projected 32×20 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 20 mm bore falls in the small band, the workhorse size for gearbox planetary positions, hydraulic pumps and general cam and linkage duty The integral inner ring brings the bore to 20 mm inside the 32×20 mm envelope; removing that ring gives the corresponding RNA/NK execution and a larger shaft for the same housing This is the choice for OEM production on soft shafts: machine the 20 mm seat to the recommended tolerance, fit the bearing, and let the inner ring provide the precision raceway -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 21.4 kN C rating and longer nominal life come without an envelope change. Typical applications include rocker arms and valve trains, two-stroke and compressor piston pins and small electric motor accessory drives, where the 32 mm outside diameter and 21.4 kN dynamic rating match the duty. In rocker arms and valve trains the unit fits a compact 20 mm seat, and in two-stroke and compressor piston pins the 61 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for small electric motor accessory drives, relying on the 20 mm width and the published 30.5 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.