RNA6912-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 RNA6912-ZW-XL model number is decoded

envelope 68×85×45 mm: 68 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 8.5 mm radial section packed with small-diameter needle rollers C is 106 kN and C0 191 kN at the 68 mm seat; the C/C0 ratio of 0.55 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 85 mm outside diameter the fatigue load limit Cur is 33 kN, the limiting speed 6,700 r/min and the thermal reference speed 3,850 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 1.56 kN/mm and per millimetre of width 2.36 kN/mm — the reason 45 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 488 g, just 0.13 g per mm² of projected 85×45 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 68 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 The thin 8.5 mm section makes the 488 g bearing sensitive to seat geometry — a tapered or lobed journal preloads part of the needle set and shows up as local pitting RNA6912-ZW-XL has no inner ring: the needle rollers run directly on the shaft journal, so the seat must be hardened (58–64 HRC) and ground to bearing raceway quality The -XL suffix is the Schaeffler X-life mark: interchangeable envelope with the basic bearing, but higher load capacity and lower running temperature at the 6,700 r/min limit. -ZW marks the double-row execution — two offset needle rows in one 68×85 mm ring pair, giving the 106 kN C rating in a housing space sized for a wide single bearing. Typical applications include small electric motor accessory drives, rocker arms and valve trains and planetary gear bearings, where the 85 mm outside diameter and 106 kN dynamic rating match the duty. In small electric motor accessory drives the unit fits a compact 68 mm seat, and in rocker arms and valve trains the 488 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for planetary gear bearings, relying on the 45 mm width and the published 191 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.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.