NAO30X47X18-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 NAO30X47X18-XL model number is decoded

envelope 30×47×18 mm: 30 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 31 kN and C0 43 kN at the 30 mm seat; the C/C0 ratio of 0.72 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 47 mm outside diameter the fatigue load limit Cur is 7.5 kN, the limiting speed 12,700 r/min and the thermal reference speed 6,900 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 1.03 kN/mm and per millimetre of width 1.72 kN/mm — the reason 18 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 119 g, just 0.14 g per mm² of projected 47×18 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 30 mm bore the 18 mm width and 31 kN C rating suit high-cycle industrial machinery rather than instrument duty Because neither ring guides axially, housing and shaft shoulders position the races; uncontrolled end float lets the rollers run off the raceway edges The inner ring gives a 30 mm plain bore inside the 47×18 mm envelope and the flangeless pack delivers C 31 kN — a frequent choice in gear change linkages and pumps As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 7.5 kN Cur value. Typical applications include planetary gear bearings, small electric motor accessory drives and gearbox selector and change linkages, where the 47 mm outside diameter and 31 kN dynamic rating match the duty. In planetary gear bearings the unit fits a compact 30 mm seat, and in small electric motor accessory drives the 119 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for gearbox selector and change linkages, relying on the 18 mm width and the published 43 kN static rating. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations. 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

• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• 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.