NKX15-Z bearing: complete specifications & equivalents
The NKX15-Z is a DIN 616 radial bearing sized 15 x 24 x 23 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 15 mm |
| Outer diameter D | 24 mm |
| Width B | 23 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 11 kN |
| Basic static load rating C0 | 14 kN |
| Fatigue load limit Pu | 1.66 kN |
| Reference speed (thermal) | 8500 rpm |
| Limiting speed (mechanical) | 7000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 47 g |
| Manufacturer designation | NKX 15 Z |
| 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 | 0.591 in |
|---|---|
| Outer diameter D | 0.945 in |
| Width B | 0.906 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) | 3 of 13 |
| Bore above smallest NKX-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NKX15 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 15×24×23 mm envelope and equivalent catalogue ratings; NKX15 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply. |
| NKXR15 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (15×24×23 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction. |
| NKXR15-Z | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (15×24×23 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 NKX15-Z model number is decoded
NKX 15 Z is a combined needle roller / thrust ball bearing with a caged thrust part: radial load on caged needle rollers, axial load on a ball thrust set with stamped cages, per SKF catalogue PUB BU/P1 17000 ch. 7.9. In SKF nomenclature NKX is the combined family: the number states 15 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.
Typical equipment & failure modes
Common applications
- pump impeller shafts with steady axial pull
- gear pairs generating one-direction axial force
- rotary indexing tables under combined load
- conveyor screw thrust ends
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
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- electrical erosion on VFD-driven shafts without brush or insulated mounting
- thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor
Selection pitfalls — read before you substitute
- On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- 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.
- Do not interchange envelope-identical needle families blindly: NKX 15 Z shares its 15×24×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- Do not treat the axial rating 10.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.
- 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 15 Z facing the working thrust.
- The 11/14 kN ratings and 47 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
Is the NKX 15 Z 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 NKX 15 Z have?
A NKX 15 Z measures 15 mm bore/Fw × 24 mm outside diameter × 23 mm width (0.591 × 0.945 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11 kN, static C0 14 kN, fatigue limit Pu 1.66 kN, limiting speed 7,000 r/min, reference speed 8,500 r/min, mass about 47 g. Axial ratings of the thrust part: dynamic Ca 10.6 kN (Ca), static C0a 18.3 kN (C0a), minimum load factor A 0.0017; the thrust set carries load in one direction only.
What does NKX 15 Z mean in SKF part numbering?
NKX = needle roller radial part + caged thrust ball part for a 15 mm shaft: 24 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX.
Does the NKX 15 Z need a hardened and ground shaft?
The radial needle part of the NKX 15 Z runs directly on the 15 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.