NKI65-25-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 NKI65-25-XL model number is decoded

envelope 65×90×25 mm: 65 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 12.5 mm radial section packed with small-diameter needle rollers C is 60 kN and C0 100 kN at the 65 mm seat; the C/C0 ratio of 0.60 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 90 mm outside diameter the fatigue load limit Cur is 17.9 kN, the limiting speed 6,300 r/min and the thermal reference speed 3,900 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 0.92 kN/mm and per millimetre of width 2.40 kN/mm — the reason 25 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 467 g, just 0.21 g per mm² of projected 90×25 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 65 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 NKI65/25-XL is supplied with a machined inner ring, so it mounts on an ordinary turned and ground shaft of normal tolerance — hardening the journal is not required This is the choice for OEM production on soft shafts: machine the 65 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 60 kN C rating and longer nominal life come without an envelope change. Typical applications include motorcycle and light-vehicle transmissions, connecting-rod small ends and two-stroke and compressor piston pins, where the 90 mm outside diameter and 60 kN dynamic rating match the duty. In motorcycle and light-vehicle transmissions the unit fits a compact 65 mm seat, and in connecting-rod small ends the 467 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for two-stroke and compressor piston pins, relying on the 25 mm width and the published 100 kN static rating. Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately. 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

• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.