NKI12-20-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 NKI12-20-XL model number is decoded

envelope 12×24×20 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 16.3 kN and C0 18.8 kN at the 12 mm seat; the C/C0 ratio of 0.87 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 3.35 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 1.36 kN/mm and per millimetre of width 0.82 kN/mm — the reason 20 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 41.9 g, just 0.09 g per mm² of projected 24×20 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 12 mm bore this is one of the smallest HR1 executions — chosen where a 24 mm envelope must carry line-contact loads that no miniature ball bearing could take Cur 3.35 kN, limiting speed 23,200 r/min, reference speed 14,200 r/min — the inner ring adds a few grams (total 41.9 g) but removes the hardening requirement As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 3.35 kN Cur value. Typical applications include agricultural machine pivots and linkages, hydraulic and pneumatic pump eccentrics and textile machine heald and cam shafts, where the 24 mm outside diameter and 16.3 kN dynamic rating match the duty. In agricultural machine pivots and linkages the unit fits a compact 12 mm seat, and in hydraulic and pneumatic pump eccentrics the 41.9 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for textile machine heald and cam shafts, relying on the 20 mm width and the published 18.8 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.