NK100-36 bearing: complete specifications & equivalents
The NK100-36 is a DIN 616 radial bearing sized 100 x 120 x 36 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 100 mm |
| Outer diameter D | 120 mm |
| Width B | 36 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 108 kN |
| Basic static load rating C0 | 250 kN |
| Fatigue load limit Pu | 31 kN |
| Reference speed (thermal) | 4000 rpm |
| Limiting speed (mechanical) | 4500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 720 g |
| Manufacturer designation | NK 100/36 |
| 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 | 3.937 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.417 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) | 44 of 46 |
| Bore above smallest NK-series size | 95 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK100-36 model number is decoded
NK 100/36 is a ribbed machined-ring needle roller bearing (no inner ring) sized 100×120×36 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 100 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 100 mm Fw for the shaft seat, 36 mm width; the 120 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. The 720 g catalogue mass and 10.0 mm radial section ((120−100)/2) frame a rating of about 1.08 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. 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
- piston-pin style pivots in hydraulic pumps
- guide rollers running on hardened tracks
- swing arms and lever pivots with oscillating duty
- cam followers built up from separate components
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- polymer cage deformation when the local temperature exceeds the 120 °C sustained limit
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- corrosion pitting from condensation in intermittently operated machinery
- 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 100 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 108/250 kN ratings are SKF catalogue values for this exact execution (NK 100/36); 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 108/250 kN ratings and 720 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
Is the NK 100/36 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 100/36 have?
A NK 100/36 measures 100 mm bore/Fw × 120 mm outside diameter × 36 mm width (3.937 × 4.724 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 108 kN, static C0 250 kN, fatigue limit Pu 31 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 720 g.
What does NK 100/36 mean in SKF part numbering?
NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 100 mm and width 36 mm, OD 120 mm comes from the dimension series, and the flanged outer ring retains the caged rollers.
Does the NK 100/36 need a hardened and ground shaft?
No. In this execution the 100 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.
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.