NKI90-36-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 NKI90-36-XL model number is decoded

envelope 90×120×36 mm: 90 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 15.0 mm radial section packed with small-diameter needle rollers C is 125 kN and C0 237 kN at the 90 mm seat; the C/C0 ratio of 0.53 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 120 mm outside diameter the fatigue load limit Cur is 42.5 kN, the limiting speed 4,600 r/min and the thermal reference speed 2,800 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 1.39 kN/mm and per millimetre of width 3.47 kN/mm — the reason 36 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 1.09 kg (1090 g), just 0.25 g per mm² of projected 120×36 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 90 mm bore belongs to the large band, where HR1 full-complement and track-roller designs deliver their highest kilonewton ratings in slow, heavily loaded machinery The 15.0 mm section still holds a full needle pack; like all needle bearings it cannot tolerate angular misalignment, so shaft and housing axes must be parallel This is the choice for OEM production on soft shafts: machine the 90 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 125 kN C rating and longer nominal life come without an envelope change. Typical applications include planetary gear bearings, small electric motor accessory drives and gearbox selector and change linkages, where the 120 mm outside diameter and 125 kN dynamic rating match the duty. In planetary gear bearings the unit fits a compact 90 mm seat, and in small electric motor accessory drives the 1.09 kg mass is part of the rotor inertia calculation. Designers also specify it for gearbox selector and change linkages, relying on the 36 mm width and the published 237 kN static rating. 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.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.