NA6917-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 NA6917-ZW-XL model number is decoded

envelope 85×120×63 mm: 85 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 17.5 mm radial section packed with small-diameter needle rollers C is 188 kN and C0 400 kN at the 85 mm seat; the C/C0 ratio of 0.47 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 120 mm outside diameter the fatigue load limit Cur is 72 kN, the limiting speed 4,600 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 2.21 kN/mm and per millimetre of width 2.98 kN/mm — the reason 63 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 2.2 kg (2200 g), just 0.29 g per mm² of projected 120×63 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 85 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 Cur 72 kN, limiting speed 4,600 r/min, reference speed 2,700 r/min — the inner ring adds a few grams (total 2200 g) but removes the hardening requirement The 17.5 mm section still holds a full needle pack; like all needle bearings it cannot tolerate angular misalignment, so shaft and housing axes must be parallel As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 72 kN Cur value. -ZW is the double-row needle-cage code; the two rows run on the same races and keep the unit separable and interchangeable with the single-row mounting space. Typical applications include copying and printing machine mechanisms, gearbox selector and change linkages and hydraulic and pneumatic pump eccentrics, where the 120 mm outside diameter and 188 kN dynamic rating match the duty. In copying and printing machine mechanisms the unit fits a compact 85 mm seat, and in gearbox selector and change linkages the 2.2 kg mass is part of the rotor inertia calculation. Designers also specify it for hydraulic and pneumatic pump eccentrics, relying on the 63 mm width and the published 400 kN static rating. 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. 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

• 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.
• 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.