NK70-35-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 NK70-35-XL model number is decoded

envelope 70×85×35 mm: 70 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 71 kN and C0 144 kN at the 70 mm seat; the C/C0 ratio of 0.49 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 85 mm outside diameter the fatigue load limit Cur is 27 kN, the limiting speed 6,600 r/min and the thermal reference speed 4,300 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 1.01 kN/mm and per millimetre of width 2.03 kN/mm — the reason 35 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 370 g, just 0.12 g per mm² of projected 85×35 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 70 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 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 thin 7.5 mm section makes the 370 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 71 kN C rating and longer nominal life come without an envelope change. Typical applications include gearbox selector and change linkages, planetary gear bearings and copying and printing machine mechanisms, where the 85 mm outside diameter and 71 kN dynamic rating match the duty. In gearbox selector and change linkages the unit fits a compact 70 mm seat, and in planetary gear bearings the 370 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for copying and printing machine mechanisms, relying on the 35 mm width and the published 144 kN static rating. 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. 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.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• 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.
• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.