NKIS45 bearing: complete specifications & equivalents
The NKIS45 is a DIN 616 radial bearing sized 45 x 72 x 22 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 72 mm |
| Width B | 22 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 44.6 kN |
| Basic static load rating C0 | 78 kN |
| Fatigue load limit Pu | 9.8 kN |
| Reference speed (thermal) | 7000 rpm |
| Limiting speed (mechanical) | 8000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 340 g |
| Manufacturer designation | NKIS 45 |
| 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 & NKIS-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 2.835 in |
| Width B | 0.866 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 13.5 mm |
| Smallest bore in NKIS-series | 15 mm |
| Largest outer diameter in NKIS-series | 95 mm |
| Width range across NKIS-series | 20–28 mm |
| Bore position in NKIS-series (smallest first) | 8 of 12 |
| Bore above smallest NKIS-series size | 30 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKIS45 model number is decoded
NKIS 45 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 45 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NKIS 45 code gives bore 45 mm and width 22 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 7,000 r/min thermal reference and 8,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 45 mm seat. Mounting: heat or press the inner ring onto the 45 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 22 mm assembly for free rotation before applying load.
Typical equipment & failure modes
Common applications
- wheel and lever pivots needing a replaceable inner ring
- conveyor roller ends and return rollers
- agricultural implement pivots and cutter heads
- electric motor armature shafts with ground seats
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
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- corrosion pitting from condensation in intermittently operated machinery
- inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact
Selection pitfalls — read before you substitute
- At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.
- 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 44.6/78 kN ratings and 340 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); 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 NKIS 45?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 13.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NKIS 45?
A NKIS 45 measures 45 mm bore/Fw × 72 mm outside diameter × 22 mm width (1.772 × 2.835 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44.6 kN, static C0 78 kN, fatigue limit Pu 9.8 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 340 g.
How is the NKIS 45 designation read?
The letters mark a machined-ring needle roller bearing with inner ring: 45 mm bore, 22 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices.
Can the NKIS 45 run on an unhardened shaft?
Yes — that is the point of this family. The NKIS 45 carries its own hardened, ground inner ring on a 45 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable.
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.