NKI100-30 bearing: complete specifications & equivalents
The NKI100-30 is a DIN 616 radial bearing sized 100 x 130 x 30 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 | 130 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 96.8 kN |
| Basic static load rating C0 | 220 kN |
| Fatigue load limit Pu | 27 kN |
| Reference speed (thermal) | 3600 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 990 g |
| Manufacturer designation | NKI 100/30 |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with 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. 7.4 machined rings with flanges, with 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 & NKI-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 1.181 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 15 mm |
| Smallest bore in NKI-series | 5 mm |
| Largest outer diameter in NKI-series | 130 mm |
| Width range across NKI-series | 12–40 mm |
| Bore position in NKI-series (smallest first) | 30 of 30 |
| Bore above smallest NKI-series size | 95 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKI100-30 model number is decoded
In SKF catalogue PUB BU/P1 17000, NKI 100/30 denotes a complete needle roller bearing for a 100 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 130 mm OD and 30 mm width. The NKI 100/30 code gives bore 100 mm and width 30 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 990 g catalogue mass and 15.0 mm radial section ((130−100)/2) frame a rating of about 0.97 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.
Typical equipment & failure modes
Common applications
- conveyor roller ends and return rollers
- agricultural implement pivots and cutter heads
- electric motor armature shafts with ground seats
- printing and paper-handling rollers
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- 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
- false brinelling of standby equipment under external vibration
- inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact
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.
- Hardness is load capacity: in families without an inner ring the 100 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.
- The quoted 96.8/220 kN ratings are SKF catalogue values for this exact execution (NKI 100/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 96.8/220 kN ratings and 990 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
What are the dimensions and ratings of the NKI 100/30?
A NKI 100/30 measures 100 mm bore/Fw × 130 mm outside diameter × 30 mm width (3.937 × 5.118 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 96.8 kN, static C0 220 kN, fatigue limit Pu 27 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 990 g.
How is the NKI 100/30 designation read?
The letters mark a machined-ring needle roller bearing with inner ring: 100 mm bore, 30 mm width, 130 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices.
Can the NKI 100/30 run on an unhardened shaft?
Yes — that is the point of this family. The NKI 100/30 carries its own hardened, ground inner ring on a 100 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable.
How should the NKI 100/30 be mounted?
Mount the inner ring on the 100 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring on 2026-09-26. Read our editorial & correction policy.