NKS35-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 NKS35-XL model number is decoded

envelope 35×50×22 mm: 35 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 7.5 mm radial section packed with small-diameter needle rollers C is 39.5 kN and C0 47 kN at the 35 mm seat; the C/C0 ratio of 0.84 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 50 mm outside diameter the fatigue load limit Cur is 8.2 kN, the limiting speed 12,300 r/min and the thermal reference speed 7,400 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 1.13 kN/mm and per millimetre of width 1.80 kN/mm — the reason 22 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 118 g, just 0.11 g per mm² of projected 50×22 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 35 mm bore this is a mainstream industrial size — conveyor drives, winches and medium gearboxes use the 22 mm width as a standard mounting space With Cur 8.2 kN and a 12,300 r/min limiting speed the unit suits pivots, rocker arms, pumps and compact gear trains running on hardened pins Omitting the inner ring frees radial space — at a 35 mm shaft the outer diameter is only 50 mm and the width 22 mm, yet C is 39.5 kN As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 8.2 kN Cur value. Typical applications include small electric motor accessory drives, rocker arms and valve trains and planetary gear bearings, where the 50 mm outside diameter and 39.5 kN dynamic rating match the duty. In small electric motor accessory drives the unit fits a compact 35 mm seat, and in rocker arms and valve trains the 118 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for planetary gear bearings, relying on the 22 mm width and the published 47 kN static rating. 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.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.