NKS43-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 NKS43-XL model number is decoded

envelope 43×58×22 mm: 43 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 7.5 mm radial section packed with small-diameter needle rollers C is 44 kN and C0 57 kN at the 43 mm seat; the C/C0 ratio of 0.77 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 58 mm outside diameter the fatigue load limit Cur is 10 kN, the limiting speed 10,200 r/min and the thermal reference speed 6,200 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 1.02 kN/mm and per millimetre of width 2.00 kN/mm — the reason 22 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 139 g, just 0.11 g per mm² of projected 58×22 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 43 mm bore this is a mainstream industrial size — conveyor drives, winches and medium gearboxes use the 22 mm width as a standard mounting space Omitting the inner ring frees radial space — at a 43 mm shaft the outer diameter is only 58 mm and the width 22 mm, yet C is 44 kN NKS43-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 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. Typical applications include textile machine heald and cam shafts, agricultural machine pivots and linkages and connecting-rod small ends, where the 58 mm outside diameter and 44 kN dynamic rating match the duty. In textile machine heald and cam shafts the unit fits a compact 43 mm seat, and in agricultural machine pivots and linkages the 139 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for connecting-rod small ends, relying on the 22 mm width and the published 57 kN static rating. On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions. 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

• On reciprocating duty ensure the stroke rotates the full needle set, or brinelling occurs at the same roller positions.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.