RNAO18X30X24-ZW-ASR1-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 RNAO18X30X24-ZW-ASR1-XL model number is decoded

envelope 18×30×24 mm: 18 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 6.0 mm radial section packed with small-diameter needle rollers C is 24.8 kN and C0 30 kN at the 18 mm seat; the C/C0 ratio of 0.83 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 30 mm outside diameter the fatigue load limit Cur is 5.4 kN, the limiting speed 21,800 r/min and the thermal reference speed 14,000 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 1.38 kN/mm and per millimetre of width 1.03 kN/mm — the reason 24 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 69 g, just 0.10 g per mm² of projected 30×24 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 18 mm bore the 24 mm width and 24.8 kN C rating suit high-cycle industrial machinery rather than instrument duty RNAO marks the flangeless needle bearing without inner ring: neither race carries ribs, so the 18 mm hardened shaft journal and the housing faces provide all axial guidance X-life status (-XL) indicates the current Schaeffler premium execution at 18 mm bore; the 30 kN C0 rating reflects the improved rolling-contact geometry. The -ZW suffix denotes a double-row (zweireihig) needle roller and cage assembly: two roller rows share the 24 mm-wide envelope for higher capacity at the same bore. The ASR groove is particularly useful on double-row -ZW executions, feeding both rows evenly across the 30 mm outer ring. Typical applications include gearbox selector and change linkages, planetary gear bearings and copying and printing machine mechanisms, where the 30 mm outside diameter and 24.8 kN dynamic rating match the duty. In gearbox selector and change linkages the unit fits a compact 18 mm seat, and in planetary gear bearings the 69 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for copying and printing machine mechanisms, relying on the 24 mm width and the published 30 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. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.

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.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.