NA4914 bearing: complete specifications & equivalents
The NA4914 is a ISO 1206 radial bearing sized 70 x 100 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 | 70 mm |
| Outer diameter D | 100 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 84.2 kN |
| Basic static load rating C0 | 163 kN |
| Fatigue load limit Pu | 20.8 kN |
| Reference speed (thermal) | 5000 rpm |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 730 g |
| Manufacturer designation | NA 4914 |
| Standard | ISO 1206 |
| 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 & NA-49-series range
| Bore d | 2.756 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 1.181 in |
| ISO bore code | 14 |
| Radial section height (D−d)/2 | 15 mm |
| Smallest bore in NA-49-series | 10 mm |
| Largest outer diameter in NA-49-series | 190 mm |
| Width range across NA-49-series | 13–50 mm |
| Bore position in NA-49-series (smallest first) | 18 of 28 |
| Bore above smallest NA-49-series size | 60 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NA4914 model number is decoded
NA 4914 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 70 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NA 4914 code gives bore 70 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. 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. Catalogue mass 730 g at 70×100×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 70 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.
Typical equipment & failure modes
Common applications
- printing and paper-handling rollers
- gearbox shafts where the journal cannot be hardened on site
- wheel and lever pivots needing a replaceable inner ring
- conveyor roller ends and return rollers
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
- Above 50 mm bore, thermal growth matters: the 70 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 70 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 84.2/163 kN ratings are SKF catalogue values for this exact execution (NA 4914); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 84.2/163 kN ratings and 730 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); 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 NA 4914?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 70 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NA 4914?
A NA 4914 measures 70 mm bore/Fw × 100 mm outside diameter × 30 mm width (2.756 × 3.937 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 84.2 kN, static C0 163 kN, fatigue limit Pu 20.8 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 730 g.
How is the NA 4914 designation read?
The letters mark a machined-ring needle roller bearing with inner ring: 70 mm bore, 30 mm width, 100 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices.
Can the NA 4914 run on an unhardened shaft?
Yes — that is the point of this family. The NA 4914 carries its own hardened, ground inner ring on a 70 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.