NK105-26 bearing: complete specifications & equivalents
The NK105-26 is a DIN 616 radial bearing sized 105 x 125 x 26 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 105 mm |
| Outer diameter D | 125 mm |
| Width B | 26 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 78.1 kN |
| Basic static load rating C0 | 166 kN |
| Fatigue load limit Pu | 20.4 kN |
| Reference speed (thermal) | 3800 rpm |
| Limiting speed (mechanical) | 4300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 540 g |
| Manufacturer designation | NK 105/26 |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & NK-series range
| Bore d | 4.134 in |
|---|---|
| Outer diameter D | 4.921 in |
| Width B | 1.024 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 10 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) | 45 of 46 |
| Bore above smallest NK-series size | 100 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK105-26 model number is decoded
NK 105/26 is a ribbed machined-ring needle roller bearing (no inner ring) sized 105×125×26 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 105 mm shaft journal completes the bearing. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 105 mm under-roller diameter and the 26 mm width, with the 125 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 540 g at 105×125×26 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.
Typical equipment & failure modes
Common applications
- cam followers built up from separate components
- crank pins and eccentrics where the hardened journal is the raceway
- gearbox planetary and idler gears on hardened pins
- piston-pin style pivots in hydraulic pumps
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- cage pocket wear and roller skew after sustained operation with too little radial preload
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- rolling-contact fatigue spalling after the rated L10 life
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
Selection pitfalls — read before you substitute
- Above 50 mm bore, thermal growth matters: the 105 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.
- The quoted 78.1/166 kN ratings are SKF catalogue values for this exact execution (NK 105/26); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.
- The 78.1/166 kN ratings and 540 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Does the NK 105/26 need a hardened and ground shaft?
No. In this execution the 105 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead.
What mounting mistakes ruin a NK 105/26?
Press on the ring faces only with a fitting sleeve, keep everything square to the 105 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs.
Is the NK 105/26 sealed?
No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty.
Which dimensions does the NK 105/26 have?
A NK 105/26 measures 105 mm bore/Fw × 125 mm outside diameter × 26 mm width (4.134 × 4.921 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 78.1 kN, static C0 166 kN, fatigue limit Pu 20.4 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 540 g.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring on 2026-09-26. Read our editorial & correction policy.