NK65-35-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 NK65-35-XL model number is decoded

envelope 65×78×35 mm: 65 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 6.5 mm radial section packed with small-diameter needle rollers C is 66 kN and C0 142 kN at the 65 mm seat; the C/C0 ratio of 0.46 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 78 mm outside diameter the fatigue load limit Cur is 26 kN, the limiting speed 7,200 r/min and the thermal reference speed 4,450 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 1.02 kN/mm and per millimetre of width 1.89 kN/mm — the reason 35 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 310 g, just 0.11 g per mm² of projected 78×35 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 65 mm bore the 78 mm outside diameter and 35 mm width target rolling stands, construction machinery and heavy gearboxes; the limiting speed drops to 7,200 r/min NK65/35-XL has no inner ring: the needle rollers run directly on the shaft journal, so the seat must be hardened (58–64 HRC) and ground to bearing raceway quality Omitting the inner ring frees radial space — at a 65 mm shaft the outer diameter is only 78 mm and the width 35 mm, yet C is 66 kN X-life status (-XL) indicates the current Schaeffler premium execution at 65 mm bore; the 142 kN C0 rating reflects the improved rolling-contact geometry. Typical applications include rocker arms and valve trains, two-stroke and compressor piston pins and small electric motor accessory drives, where the 78 mm outside diameter and 66 kN dynamic rating match the duty. In rocker arms and valve trains the unit fits a compact 65 mm seat, and in two-stroke and compressor piston pins the 310 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for small electric motor accessory drives, relying on the 35 mm width and the published 142 kN static rating. Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone. 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

• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.