NK75-35-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 NK75-35-XL model number is decoded

envelope 75×92×35 mm: 75 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 8.5 mm radial section packed with small-diameter needle rollers C is 87 kN and C0 162 kN at the 75 mm seat; the C/C0 ratio of 0.54 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 92 mm outside diameter the fatigue load limit Cur is 28.5 kN, the limiting speed 6,100 r/min and the thermal reference speed 3,950 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 1.16 kN/mm and per millimetre of width 2.49 kN/mm — the reason 35 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 445 g, just 0.14 g per mm² of projected 92×35 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 75 mm bore the 92 mm outside diameter and 35 mm width target rolling stands, construction machinery and heavy gearboxes; the limiting speed drops to 6,100 r/min The thin 8.5 mm section makes the 445 g bearing sensitive to seat geometry — a tapered or lobed journal preloads part of the needle set and shows up as local pitting The hardness requirement is unforgiving: below about 58 HRC the 75 mm journal brinels under the 162 kN static rating, and roughness above raceway finish accelerates roller wear As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 28.5 kN Cur value. Typical applications include gearbox selector and change linkages, planetary gear bearings and copying and printing machine mechanisms, where the 92 mm outside diameter and 87 kN dynamic rating match the duty. In gearbox selector and change linkages the unit fits a compact 75 mm seat, and in planetary gear bearings the 445 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 162 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. 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

• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• 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.
• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.