NK105-36-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 NK105-36-XL model number is decoded

envelope 105×125×36 mm: 105 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 10.0 mm radial section packed with small-diameter needle rollers C is 129 kN and C0 250 kN at the 105 mm seat; the C/C0 ratio of 0.52 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 125 mm outside diameter the fatigue load limit Cur is 44.5 kN, the limiting speed 4,400 r/min and the thermal reference speed 2,850 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 1.23 kN/mm and per millimetre of width 3.58 kN/mm — the reason 36 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 713 g, just 0.16 g per mm² of projected 125×36 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 105 mm bore the 125 mm outside diameter and 36 mm width target rolling stands, construction machinery and heavy gearboxes; the limiting speed drops to 4,400 r/min Omitting the inner ring frees radial space — at a 105 mm shaft the outer diameter is only 125 mm and the width 36 mm, yet C is 129 kN With Cur 44.5 kN and a 4,400 r/min limiting speed the unit suits pivots, rocker arms, pumps and compact gear trains running on hardened pins X-life status (-XL) indicates the current Schaeffler premium execution at 105 mm bore; the 250 kN C0 rating reflects the improved rolling-contact geometry. Typical applications include gearbox selector and change linkages, planetary gear bearings and copying and printing machine mechanisms, where the 125 mm outside diameter and 129 kN dynamic rating match the duty. In gearbox selector and change linkages the unit fits a compact 105 mm seat, and in planetary gear bearings the 713 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for copying and printing machine mechanisms, relying on the 36 mm width and the published 250 kN static rating. Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO. 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

• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• 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.