NK9-12-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 NK9-12-TV-XL model number is decoded

envelope 9×16×12 mm: 9 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 3.5 mm radial section packed with small-diameter needle rollers C is 5.1 kN and C0 5 kN at the 9 mm seat; the C/C0 ratio of 1.02 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 16 mm outside diameter the fatigue load limit Cur is 0.86 kN, the limiting speed 31,000 r/min and the thermal reference speed 32,000 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 0.57 kN/mm and per millimetre of width 0.42 kN/mm — the reason 12 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 10.3 g, just 0.05 g per mm² of projected 16×12 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 9 mm bore this is one of the smallest HR1 executions — chosen where a 16 mm envelope must carry line-contact loads that no miniature ball bearing could take With Cur 0.86 kN and a 31,000 r/min limiting speed the unit suits pivots, rocker arms, pumps and compact gear trains running on hardened pins Omitting the inner ring frees radial space — at a 9 mm shaft the outer diameter is only 16 mm and the width 12 mm, yet C is 5.1 kN -XL means this is an X-life bearing — Schaeffler's upgraded performance level with smoother raceways, so the 5.1 kN C rating and longer nominal life come without an envelope change. With the -TV polyamide cage the rollers are positively separated, so the 9 mm bearing suits continuous rotation rather than the slow oscillating duty where cageless packs are chosen. Typical applications include connecting-rod small ends, textile machine heald and cam shafts and motorcycle and light-vehicle transmissions, where the 16 mm outside diameter and 5.1 kN dynamic rating match the duty. In connecting-rod small ends the unit fits a compact 9 mm seat, and in textile machine heald and cam shafts the 10.3 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for motorcycle and light-vehicle transmissions, relying on the 12 mm width and the published 5 kN static rating. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations. Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
• Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone.
• Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.