NK90-35-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 NK90-35-XL model number is decoded

envelope 90×110×35 mm: 90 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 116 kN and C0 208 kN at the 90 mm seat; the C/C0 ratio of 0.56 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 110 mm outside diameter the fatigue load limit Cur is 38 kN, the limiting speed 5,100 r/min and the thermal reference speed 3,250 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 1.29 kN/mm and per millimetre of width 3.31 kN/mm — the reason 35 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 630 g, just 0.16 g per mm² of projected 110×35 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 90 mm bore this is a heavy-industrial bearing: 630 g of stiff ring and roller set, specified where rigidity matters more than speed The hardness requirement is unforgiving: below about 58 HRC the 90 mm journal brinels under the 208 kN static rating, and roughness above raceway finish accelerates roller wear This bearing accepts axial displacement between shaft and housing because the rollers rotate on the free journal; it locates nothing axially and must be flanked by guide faces The -XL suffix is the Schaeffler X-life mark: interchangeable envelope with the basic bearing, but higher load capacity and lower running temperature at the 5,100 r/min limit. Typical applications include connecting-rod small ends, textile machine heald and cam shafts and motorcycle and light-vehicle transmissions, where the 110 mm outside diameter and 116 kN dynamic rating match the duty. In connecting-rod small ends the unit fits a compact 90 mm seat, and in textile machine heald and cam shafts the 630 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for motorcycle and light-vehicle transmissions, relying on the 35 mm width and the published 208 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. On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.

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.
• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• 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.