RNA6918-ZW-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 RNA6918-ZW-XL model number is decoded

envelope 105×125×63 mm: 105 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 10.0 mm radial section packed with small-diameter needle rollers C is 195 kN and C0 425 kN at the 105 mm seat; the C/C0 ratio of 0.46 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 125 mm outside diameter the fatigue load limit Cur is 76 kN, the limiting speed 4,400 r/min and the thermal reference speed 2,700 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 1.86 kN/mm and per millimetre of width 3.10 kN/mm — the reason 63 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 1.33 kg (1330 g), just 0.17 g per mm² of projected 125×63 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 105 mm bore belongs to the large band, where HR1 full-complement and track-roller designs deliver their highest kilonewton ratings in slow, heavily loaded machinery Reading the RNA69 prefix: a machined (not drawn-cup) outer ring with the needle complement; an inner ring from the IR series can be added later if the shaft cannot be hardened -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 195 kN C rating and longer nominal life come without an envelope change. The -ZW double-row pack explains the high C0 of 425 kN in this thin-section bearing — two rows support the static peak that a single row could not. Typical applications include agricultural machine pivots and linkages, hydraulic and pneumatic pump eccentrics and textile machine heald and cam shafts, where the 125 mm outside diameter and 195 kN dynamic rating match the duty. In agricultural machine pivots and linkages the unit fits a compact 105 mm seat, and in hydraulic and pneumatic pump eccentrics the 1.33 kg mass is part of the rotor inertia calculation. Designers also specify it for textile machine heald and cam shafts, relying on the 63 mm width and the published 425 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. 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

• 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.
• 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.