NKI25-20-TV-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 NKI25-20-TV-XL model number is decoded

envelope 25×38×20 mm: 25 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 6.5 mm radial section packed with small-diameter needle rollers C is 27.5 kN and C0 39 kN at the 25 mm seat; the C/C0 ratio of 0.71 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 38 mm outside diameter the fatigue load limit Cur is 7 kN, the limiting speed 15,300 r/min and the thermal reference speed 8,100 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 1.10 kN/mm and per millimetre of width 1.38 kN/mm — the reason 20 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 75.8 g, just 0.10 g per mm² of projected 38×20 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 25 mm bore falls in the small band, the workhorse size for gearbox planetary positions, hydraulic pumps and general cam and linkage duty The inner ring is separable, so the outer-ring/roller assembly can be pressed into the housing first; the 39 kN C0 rating still assumes full rigid support under both rings As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 7 kN Cur value. The -TV cage is part of the speed story here: cage-guided kinematics permit the published 15,300 r/min limiting speed without roller-to-roller sliding. Typical applications include hydraulic and pneumatic pump eccentrics, copying and printing machine mechanisms and agricultural machine pivots and linkages, where the 38 mm outside diameter and 27.5 kN dynamic rating match the duty. In hydraulic and pneumatic pump eccentrics the unit fits a compact 25 mm seat, and in copying and printing machine mechanisms the 75.8 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for agricultural machine pivots and linkages, relying on the 20 mm width and the published 39 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. 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

• 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.
• 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.