NKI35-20-TV-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 NKI35-20-TV-XL model number is decoded

envelope 35×50×20 mm: 35 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 7.5 mm radial section packed with small-diameter needle rollers C is 33.5 kN and C0 56 kN at the 35 mm seat; the C/C0 ratio of 0.60 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 50 mm outside diameter the fatigue load limit Cur is 10 kN, the limiting speed 11,400 r/min and the thermal reference speed 6,100 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 0.96 kN/mm and per millimetre of width 1.68 kN/mm — the reason 20 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 122 g, just 0.12 g per mm² of projected 50×20 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 35 mm bore this is a mainstream industrial size — conveyor drives, winches and medium gearboxes use the 20 mm width as a standard mounting space The integral inner ring brings the bore to 35 mm inside the 50×20 mm envelope; removing that ring gives the corresponding RNA/NK execution and a larger shaft for the same housing The 7.5 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 10 kN Cur value. The -TV suffix specifies a glass-fibre reinforced polyamide 66 window-type cage; it spaces the rollers for low friction and is the reason the limiting speed can reach 11,400 r/min. Typical applications include two-stroke and compressor piston pins, motorcycle and light-vehicle transmissions and rocker arms and valve trains, where the 50 mm outside diameter and 33.5 kN dynamic rating match the duty. In two-stroke and compressor piston pins the unit fits a compact 35 mm seat, and in motorcycle and light-vehicle transmissions the 122 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for rocker arms and valve trains, relying on the 20 mm width and the published 56 kN static rating. Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately. Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Keep the specified radial clearance; an oversized shaft or heavy interference removes it and the needles bind hot immediately.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• 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.