NKI42-30-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 NKI42-30-XL model number is decoded

envelope 42×57×30 mm: 42 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 7.5 mm radial section packed with small-diameter needle rollers C is 48.5 kN and C0 94 kN at the 42 mm seat; the C/C0 ratio of 0.52 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 57 mm outside diameter the fatigue load limit Cur is 17.8 kN, the limiting speed 9,800 r/min and the thermal reference speed 5,400 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 1.15 kN/mm and per millimetre of width 1.62 kN/mm — the reason 30 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 222 g, just 0.13 g per mm² of projected 57×30 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 42 mm bore this is a mainstream industrial size — conveyor drives, winches and medium gearboxes use the 30 mm width as a standard mounting space This is the choice for OEM production on soft shafts: machine the 42 mm seat to the recommended tolerance, fit the bearing, and let the inner ring provide the precision raceway The 7.5 mm section still holds a full needle pack; like all needle bearings it cannot tolerate angular misalignment, so shaft and housing axes must be parallel X-life status (-XL) indicates the current Schaeffler premium execution at 42 mm bore; the 94 kN C0 rating reflects the improved rolling-contact geometry. Typical applications include textile machine heald and cam shafts, agricultural machine pivots and linkages and connecting-rod small ends, where the 57 mm outside diameter and 48.5 kN dynamic rating match the duty. In textile machine heald and cam shafts the unit fits a compact 42 mm seat, and in agricultural machine pivots and linkages the 222 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for connecting-rod small ends, relying on the 30 mm width and the published 94 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. 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

• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• 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.