NKX17 bearing: complete specifications & equivalents
The NKX17 is a DIN 616 radial bearing sized 17 x 26 x 25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 26 mm |
| Width B | 25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 12.1 kN |
| Basic static load rating C0 | 16.6 kN |
| Fatigue load limit Pu | 1.96 kN |
| Reference speed (thermal) | 8500 rpm |
| Limiting speed (mechanical) | 12000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 53 g |
| Manufacturer designation | NKX 17 |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part); 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 & NKX-series range
| Bore d | 0.669 in |
|---|---|
| Outer diameter D | 1.024 in |
| Width B | 0.984 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 4.5 mm |
| Smallest bore in NKX-series | 10 mm |
| Largest outer diameter in NKX-series | 85 mm |
| Width range across NKX-series | 23–40 mm |
| Bore position in NKX-series (smallest first) | 4 of 13 |
| Bore above smallest NKX-series size | 7 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NKX17-Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 17×26×25 mm envelope and equivalent catalogue ratings; NKX17-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply. |
| NKXR17 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (17×26×25 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction. |
| NKXR17-Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (17×26×25 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction. |
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 NKX17 model number is decoded
NKX 17 integrates two bearings in one envelope: needle rollers for the radial load on a 17 mm seat, and a cage-held thrust ball set for axial loads up to 10.8 kN (Ca) dynamic. The NKX 17 figure gives the 17 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. Caged thrust balls allow higher speeds than the full complement NX execution in the same envelope; the trade-off is a somewhat lower axial rating — compare the Ca figures before choosing. The minimum load factor A 0.002 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.
Typical equipment & failure modes
Common applications
- turntable and swivel mounts
- machine tool feed spindles with one-direction thrust
- pump impeller shafts with steady axial pull
- gear pairs generating one-direction axial force
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- 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
- brinelling of raceways from impact or pressing force transmitted through the rolling elements
- thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry
Selection pitfalls — read before you substitute
- On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- 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.
- Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.
- The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 17 facing the working thrust.
- Minimum axial load is a real requirement: below factor A 0.002 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.
- The 12.1/16.6 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
What limits the service life of a NKX 17?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NKX 17?
A NKX 17 measures 17 mm bore/Fw × 26 mm outside diameter × 25 mm width (0.669 × 1.024 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 12,000 r/min, reference speed 8,500 r/min, mass about 53 g. Axial ratings of the thrust part: dynamic Ca 10.8 kN (Ca), static C0a 19.6 kN (C0a), minimum load factor A 0.002; the thrust set carries load in one direction only.
How is the NKX 17 designation read?
NKX = needle roller radial part + caged thrust ball part for a 17 mm shaft: 26 mm OD, 25 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX.
Can the NKX 17 run on an unhardened shaft?
The radial needle part of the NKX 17 runs directly on the 17 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part on 2026-09-26. Read our editorial & correction policy.