NK12-16-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 NK12-16-XL model number is decoded

envelope 12×19×16 mm: 12 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 10.1 kN and C0 11 kN at the 12 mm seat; the C/C0 ratio of 0.92 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 19 mm outside diameter the fatigue load limit Cur is 1.95 kN, the limiting speed 26,500 r/min and the thermal reference speed 21,600 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 0.84 kN/mm and per millimetre of width 0.63 kN/mm — the reason 16 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 15.9 g, just 0.05 g per mm² of projected 19×16 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 12 mm bore this is one of the smallest HR1 executions — chosen where a 19 mm envelope must carry line-contact loads that no miniature ball bearing could take NK12/16-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 Omitting the inner ring frees radial space — at a 12 mm shaft the outer diameter is only 19 mm and the width 16 mm, yet C is 10.1 kN The -XL suffix is the Schaeffler X-life mark: interchangeable envelope with the basic bearing, but higher load capacity and lower running temperature at the 26,500 r/min limit. Typical applications include small electric motor accessory drives, rocker arms and valve trains and planetary gear bearings, where the 19 mm outside diameter and 10.1 kN dynamic rating match the duty. In small electric motor accessory drives the unit fits a compact 12 mm seat, and in rocker arms and valve trains the 15.9 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for planetary gear bearings, relying on the 16 mm width and the published 11 kN static rating. Open ends draw contamination directly onto the needles; specify sealed or shielded positions in dusty environments rather than relying on grease alone. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

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