RNAO30X40X17-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 RNAO30X40X17-XL model number is decoded

envelope 30×40×17 mm: 30 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 5.0 mm radial section packed with small-diameter needle rollers C is 22.1 kN and C0 34 kN at the 30 mm seat; the C/C0 ratio of 0.65 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 40 mm outside diameter the fatigue load limit Cur is 5.4 kN, the limiting speed 15,100 r/min and the thermal reference speed 8,800 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 0.74 kN/mm and per millimetre of width 1.30 kN/mm — the reason 17 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 60 g, just 0.09 g per mm² of projected 40×17 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 30 mm bore falls in the small band, the workhorse size for gearbox planetary positions, hydraulic pumps and general cam and linkage duty Cur 5.4 kN and speeds up to 15,100 r/min suit planetary gears, connecting rods and pump eccentrics where space is dictated by the shaft diameter At 60 g the assembly is easy to drop into a connecting-rod eye, but without ribs even a small axial offset skews the needles — end float must be controlled by the surrounding parts As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 5.4 kN Cur value. Typical applications include two-stroke and compressor piston pins, motorcycle and light-vehicle transmissions and rocker arms and valve trains, where the 40 mm outside diameter and 22.1 kN dynamic rating match the duty. In two-stroke and compressor piston pins the unit fits a compact 30 mm seat, and in motorcycle and light-vehicle transmissions the 60 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for rocker arms and valve trains, relying on the 17 mm width and the published 34 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.