NA4915-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 NA4915-XL model number is decoded

envelope 75×105×30 mm: 75 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 15.0 mm radial section packed with small-diameter needle rollers C is 97 kN and C0 162 kN at the 75 mm seat; the C/C0 ratio of 0.60 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 29 kN, the limiting speed 5,400 r/min and the thermal reference speed 3,100 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 3.23 kN/mm — the reason 30 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 775 g, just 0.25 g per mm² of projected 105×30 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 75 mm bore the 105 mm outside diameter and 30 mm width target rolling stands, construction machinery and heavy gearboxes; the limiting speed drops to 5,400 r/min Cur 29 kN, limiting speed 5,400 r/min, reference speed 3,100 r/min — the inner ring adds a few grams (total 775 g) but removes the hardening requirement The 15.0 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 75 mm bore; the 162 kN C0 rating reflects the improved rolling-contact geometry. Typical applications include small electric motor accessory drives, rocker arms and valve trains and planetary gear bearings, where the 105 mm outside diameter and 97 kN dynamic rating match the duty. In small electric motor accessory drives the unit fits a compact 75 mm seat, and in rocker arms and valve trains the 775 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for planetary gear bearings, relying on the 30 mm width and the published 162 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.