NKI40-20-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 NKI40-20-TV-XL model number is decoded

envelope 40×55×20 mm: 40 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 7.5 mm radial section packed with small-diameter needle rollers C is 35 kN and C0 62 kN at the 40 mm seat; the C/C0 ratio of 0.56 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 55 mm outside diameter the fatigue load limit Cur is 11 kN, the limiting speed 10,200 r/min and the thermal reference speed 5,600 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 0.88 kN/mm and per millimetre of width 1.75 kN/mm — the reason 20 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 136 g, just 0.12 g per mm² of projected 55×20 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 40 mm bore this is a mainstream industrial size — conveyor drives, winches and medium gearboxes use the 20 mm width as a standard mounting space Cur 11 kN, limiting speed 10,200 r/min, reference speed 5,600 r/min — the inner ring adds a few grams (total 136 g) but removes the hardening requirement Reading the NKI prefix: machined-ring needle bearing with inner ring, one roller row, capable of pure radial load at 35 kN C 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 10,200 r/min limit. -TV denotes the PA66 cage: light, quiet and self-lubricating in dry-running moments, but limited by the polymer's continuous-temperature ceiling well below the ring steel's. Typical applications include agricultural machine pivots and linkages, hydraulic and pneumatic pump eccentrics and textile machine heald and cam shafts, where the 55 mm outside diameter and 35 kN dynamic rating match the duty. In agricultural machine pivots and linkages the unit fits a compact 40 mm seat, and in hydraulic and pneumatic pump eccentrics the 136 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 62 kN static rating. Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately. 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.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.
• 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.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.