NK26-16-XL bearing: complete specifications & equivalents

The NK26-16-XL is a ISO 15 radial bearing sized 26 x 34 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 = 34 mm d = 26 B = 16 mm side section front view
Principal dimensions: bore d 26 mm, outer diameter D 34 mm, width B 16 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand FAG
Bore diameter d 26 mm
Outer diameter D 34 mm
Width B 16 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage steel
Basic dynamic load rating C 17.3 kN
Basic static load rating C0 23.6 kN
Fatigue load limit Pu 4.45 kN
Reference speed (thermal) 10300 rpm
Limiting speed (mechanical) 17200 rpm
Operating temperature -40 to +120 °C
Mass 34 g
Manufacturer designation NK26/16-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 & nk-series range

Bore d 1.024 in
Outer diameter D 1.339 in
Width B 0.63 in
ISO bore code —
Radial section height (D−d)/2 4 mm
Smallest bore in nk-series 5 mm
Largest outer diameter in nk-series 130 mm
Width range across nk-series 10–40 mm
Bore position in nk-series (smallest first) 19 of 46
Bore above smallest nk-series size 21 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
NK26-16 SKF partial
Main dimensions match; tolerances, seals or internal clearance differ.
Same 26×34×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting.
NK26-20 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 NK26-16-XL model number is decoded

envelope 26×34×16 mm: 26 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 4.0 mm radial section packed with small-diameter needle rollers C is 17.3 kN and C0 23.6 kN at the 26 mm seat; the C/C0 ratio of 0.73 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 34 mm outside diameter the fatigue load limit Cur is 4.45 kN, the limiting speed 17,200 r/min and the thermal reference speed 10,300 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 0.67 kN/mm and per millimetre of width 1.08 kN/mm — the reason 16 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 34 g, just 0.06 g per mm² of projected 34×16 mm envelope, which keeps unbalanced forces low in fast-actuating linkages the 26 mm bore falls in the small band, the workhorse size for gearbox planetary positions, hydraulic pumps and general cam and linkage duty Omitting the inner ring frees radial space — at a 26 mm shaft the outer diameter is only 34 mm and the width 16 mm, yet C is 17.3 kN This bearing accepts axial displacement between shaft and housing because the rollers rotate on the free journal; it locates nothing axially and must be flanked by guide faces 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 17,200 r/min limit. Typical applications include copying and printing machine mechanisms, gearbox selector and change linkages and hydraulic and pneumatic pump eccentrics, where the 34 mm outside diameter and 17.3 kN dynamic rating match the duty. In copying and printing machine mechanisms the unit fits a compact 26 mm seat, and in gearbox selector and change linkages the 34 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for hydraulic and pneumatic pump eccentrics, relying on the 16 mm width and the published 23.6 kN static rating. 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.

Typical equipment & failure modes

Common applications

  • gearbox selector and change linkages
  • two-stroke and compressor piston pins
  • copying and printing machine mechanisms
  • hydraulic and pneumatic pump eccentrics

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

  • 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.
  • 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.

Frequently asked questions

What are the dimensions of the NK26/16-XL?

The NK26/16-XL is a NK machined-ring needle roller bearing without inner ring with 34 mm outside diameter, 26 mm bore and 16 mm width, envelope 26×34×16 mm. Mass is 34 g.

What does the NK26/16-XL designation mean in the FAG/INA HR1 catalogue?

NK26/16-XL identifies this NK machined-ring needle roller bearing without inner ring in the Schaeffler HR1 rolling bearings catalogue; the -XL suffix marks the X-life execution. The envelope is 26×34×16 mm and the catalogue ratings are C 17.3 kN, C0 23.6 kN, Cur 4.45 kN.

What is the load capacity of the NK26/16-XL?

The basic dynamic load rating C is 17.3 kN and the basic static load rating C0 is 23.6 kN; the fatigue load limit Cur is 4.45 kN.

What is the maximum speed of the NK26/16-XL?

The limiting speed is 17,200 r/min and the thermal reference speed is 10,300 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.

Can the NK26/16-XL run directly on an ordinary shaft?

Not on a soft shaft. The NK26/16-XL has no inner ring, so the 26 mm journal itself is the raceway: harden it to 58–64 HRC and finish-grind to the catalogue journal tolerance. Where the shaft cannot be hardened, use the corresponding with-inner-ring execution instead.

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