NA49-28-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 NA49-28-XL model number is decoded

envelope 28×45×17 mm: 28 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 8.5 mm radial section packed with small-diameter needle rollers C is 27.5 kN and C0 33.5 kN at the 28 mm seat; the C/C0 ratio of 0.82 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 45 mm outside diameter the fatigue load limit Cur is 6.2 kN, the limiting speed 13,600 r/min and the thermal reference speed 7,400 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 0.98 kN/mm and per millimetre of width 1.62 kN/mm — the reason 17 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 97.7 g, just 0.13 g per mm² of projected 45×17 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 28 mm bore the 17 mm width and 27.5 kN C rating suit high-cycle industrial machinery rather than instrument duty This is the choice for OEM production on soft shafts: machine the 28 mm seat to the recommended tolerance, fit the bearing, and let the inner ring provide the precision raceway X-life status (-XL) indicates the current Schaeffler premium execution at 28 mm bore; the 33.5 kN C0 rating reflects the improved rolling-contact geometry. Typical applications include connecting-rod small ends, textile machine heald and cam shafts and motorcycle and light-vehicle transmissions, where the 45 mm outside diameter and 27.5 kN dynamic rating match the duty. In connecting-rod small ends the unit fits a compact 28 mm seat, and in textile machine heald and cam shafts the 97.7 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for motorcycle and light-vehicle transmissions, relying on the 17 mm width and the published 33.5 kN static rating. 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. Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.