NK85-35-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 NK85-35-XL model number is decoded

envelope 85×105×35 mm: 85 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 111 kN and C0 193 kN at the 85 mm seat; the C/C0 ratio of 0.58 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 105 mm outside diameter the fatigue load limit Cur is 35 kN, the limiting speed 5,400 r/min and the thermal reference speed 3,450 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 1.31 kN/mm and per millimetre of width 3.17 kN/mm — the reason 35 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 600 g, just 0.16 g per mm² of projected 105×35 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 85 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 The thin 10.0 mm section makes the 600 g bearing sensitive to seat geometry — a tapered or lobed journal preloads part of the needle set and shows up as local pitting -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 111 kN C rating and longer nominal life come without an envelope change. Typical applications include hydraulic and pneumatic pump eccentrics, copying and printing machine mechanisms and agricultural machine pivots and linkages, where the 105 mm outside diameter and 111 kN dynamic rating match the duty. In hydraulic and pneumatic pump eccentrics the unit fits a compact 85 mm seat, and in copying and printing machine mechanisms the 600 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for agricultural machine pivots and linkages, relying on the 35 mm width and the published 193 kN static rating. 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. Adding an IR inner ring changes the envelope logic: the same outer assembly then fits a smaller shaft — recheck bore, clearance and ratings when substituting.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Adding an IR inner ring changes the envelope logic: the same outer assembly then fits a smaller shaft — recheck bore, clearance and ratings when substituting.
• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.