NA4928-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 NA4928-XL model number is decoded

envelope 140×190×50 mm: 140 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 25.0 mm radial section packed with small-diameter needle rollers C is 237 kN and C0 500 kN at the 140 mm seat; the C/C0 ratio of 0.47 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 190 mm outside diameter the fatigue load limit Cur is 79 kN, the limiting speed 2,900 r/min and the thermal reference speed 1,860 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 1.69 kN/mm and per millimetre of width 4.74 kN/mm — the reason 50 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 4.15 kg (4150 g), just 0.44 g per mm² of projected 190×50 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 140 mm bore this is among the largest catalogue sizes; the 2,900 r/min limiting speed confirms a slow-speed, extreme-load application such as a slewing or rolling-mill position The inner ring is separable, so the outer-ring/roller assembly can be pressed into the housing first; the 500 kN C0 rating still assumes full rigid support under both rings Reading the NA49 prefix: machined-ring needle bearing with inner ring, one roller row, capable of pure radial load at 237 kN C -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 237 kN C rating and longer nominal life come without an envelope change. Typical applications include connecting-rod small ends, textile machine heald and cam shafts and motorcycle and light-vehicle transmissions, where the 190 mm outside diameter and 237 kN dynamic rating match the duty. In connecting-rod small ends the unit fits a compact 140 mm seat, and in textile machine heald and cam shafts the 4.15 kg mass is part of the rotor inertia calculation. Designers also specify it for motorcycle and light-vehicle transmissions, relying on the 50 mm width and the published 500 kN static rating. On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions. Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.