NA6912-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 NA6912-ZW-XL model number is decoded

envelope 60×85×45 mm: 60 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 12.5 mm radial section packed with small-diameter needle rollers C is 106 kN and C0 191 kN at the 60 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 3,700 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 1.77 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 808 g, just 0.21 g per mm² of projected 85×45 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 60 mm bore places this bearing in the medium band, where the 85 mm envelope already carries ratings in the tens of kilonewtons Cur 33 kN, limiting speed 6,700 r/min, reference speed 3,700 r/min — the inner ring adds a few grams (total 808 g) but removes the hardening requirement The inner ring is separable, so the outer-ring/roller assembly can be pressed into the housing first; the 191 kN C0 rating still assumes full rigid support under both rings The -XL suffix marks the X-life execution: refined raceway topography and upgraded materials lift the basic ratings versus the non-X-life bearing at the same 60×85×45 mm envelope. Reading -ZW: two needle rows instead of one; the load is spread over the 45 mm width while the outside diameter stays a compact 85 mm. Typical applications include motorcycle and light-vehicle transmissions, connecting-rod small ends and two-stroke and compressor piston pins, where the 85 mm outside diameter and 106 kN dynamic rating match the duty. In motorcycle and light-vehicle transmissions the unit fits a compact 60 mm seat, and in connecting-rod small ends the 808 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for two-stroke and compressor piston pins, relying on the 45 mm width and the published 191 kN static rating. On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions. 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.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• 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.
• 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.