NKI20-16-XL bearing: complete specifications & equivalents

The NKI20-16-XL is a ISO 15 radial bearing sized 20 x 32 x 16 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 32 mm d = 20 B = 16 mm side section front view
Principal dimensions: bore d 20 mm, outer diameter D 32 mm, width B 16 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand FAG
Bore diameter d 20 mm
Outer diameter D 32 mm
Width B 16 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel
Basic dynamic load rating C 16.9 kN
Basic static load rating C0 22.3 kN
Fatigue load limit Pu 4.2 kN
Reference speed (thermal) 10100 rpm
Limiting speed (mechanical) 18500 rpm
Operating temperature -40 to +120 °C
Mass 49 g
Manufacturer designation NKI20/16-XL
Standard ISO 15
Catalog version HR1 2026-09-25
Last verified 2026-09-30

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.

Dimensions in inches & nki-series range

Bore d 0.787 in
Outer diameter D 1.26 in
Width B 0.63 in
ISO bore code —
Radial section height (D−d)/2 6 mm
Smallest bore in nki-series 5 mm
Largest outer diameter in nki-series 130 mm
Width range across nki-series 12–40 mm
Bore position in nki-series (smallest first) 9 of 30
Bore above smallest nki-series size 15 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
NKI20-16 SKF full
Dimensions and internal design equivalent — standard interchange.
Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier.
NKI20-20 SKF verify
Commonly quoted cross reference; confirm against the target catalog before ordering.
Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue.

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 NKI20-16-XL model number is decoded

envelope 20×32×16 mm: 20 mm bore accepts a normal-tolerance machined shaft via the integral inner ring, with a thin 6.0 mm radial section packed with small-diameter needle rollers C is 16.9 kN and C0 22.3 kN at the 20 mm seat; the C/C0 ratio of 0.76 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 32 mm outside diameter the fatigue load limit Cur is 4.2 kN, the limiting speed 18,500 r/min and the thermal reference speed 10,100 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 0.84 kN/mm and per millimetre of width 1.06 kN/mm — the reason 16 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 49 g, just 0.10 g per mm² of projected 32×16 mm envelope, which keeps unbalanced forces low in fast-actuating linkages with a 20 mm bore the 16 mm width and 16.9 kN C rating suit high-cycle industrial machinery rather than instrument duty This is the choice for OEM production on soft shafts: machine the 20 mm seat to the recommended tolerance, fit the bearing, and let the inner ring provide the precision raceway 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 18,500 r/min limit. Typical applications include planetary gear bearings, small electric motor accessory drives and gearbox selector and change linkages, where the 32 mm outside diameter and 16.9 kN dynamic rating match the duty. In planetary gear bearings the unit fits a compact 20 mm seat, and in small electric motor accessory drives the 49 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for gearbox selector and change linkages, relying on the 16 mm width and the published 22.3 kN static rating. 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. 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

Common applications

  • hydraulic and pneumatic pump eccentrics
  • small electric motor accessory drives
  • agricultural machine pivots and linkages
  • textile machine heald and cam shafts

Known failure patterns

  • journal brinelling when a no-inner-ring bearing runs on a shaft hardened below 58 HRC or finished too rough
  • needle skewing and jamming after momentary unloading of a flangeless (RNAO/NAO) pack
  • raceway pitting from contamination drawn through the open ends of an unsealed bearing
  • edge loading at the roller ends from a tapered or lobed shaft seat
  • cage damage from shock loading or from pressing the bearing through the wrong ring
  • lubricant starvation on fast reciprocating strokes that never fully rotate the needles
  • false brinelling during stationary transport vibration
  • spalling from excessive interference that removes the radial clearance
  • roller wear from misaligned connecting-rod eyes and rocker bores

Selection pitfalls — read before you substitute

  • 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.
  • 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.

Frequently asked questions

What are the dimensions of the NKI20/16-XL?

The NKI20/16-XL is a NKI machined-ring needle roller bearing with inner ring with 32 mm outside diameter, 20 mm bore and 16 mm width, envelope 20×32×16 mm. Mass is 49 g.

What does the NKI20/16-XL designation mean in the FAG/INA HR1 catalogue?

NKI20/16-XL identifies this NKI machined-ring needle roller bearing with inner ring in the Schaeffler HR1 rolling bearings catalogue; the -XL suffix marks the X-life execution. The envelope is 20×32×16 mm and the catalogue ratings are C 16.9 kN, C0 22.3 kN, Cur 4.2 kN.

What is the load capacity of the NKI20/16-XL?

The basic dynamic load rating C is 16.9 kN and the basic static load rating C0 is 22.3 kN; the fatigue load limit Cur is 4.2 kN.

What is the maximum speed of the NKI20/16-XL?

The limiting speed is 18,500 r/min and the thermal reference speed is 10,100 r/min. In the Schaeffler catalogue the reference speed is the thermally permissible running speed under defined load; the lower of the two values governs each application.

How is the NKI20/16-XL mounted on the shaft?

The integral inner ring accepts an ordinary ground shaft at the 20 mm nominal bore with the recommended normal bearing-seat tolerance; no hardening is required. The ring is separable, so the outer assembly can be pressed into the housing first and the inner ring fitted with the shaft.

Reviewed & verified by the MPN Base engineering desk against source catalog HR1 2026-09-25 on 2026-09-30. Read our editorial & correction policy.