RNA4906 bearing: complete specifications & equivalents
The RNA4906 is a ISO 1206 radial bearing sized 35 x 47 x 17 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 35 mm |
| Outer diameter D | 47 mm |
| Width B | 17 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 25.5 kN |
| Basic static load rating C0 | 39 kN |
| Fatigue load limit Pu | 4.65 kN |
| Reference speed (thermal) | 11000 rpm |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 69 g |
| Manufacturer designation | RNA 4906 |
| Standard | ISO 1206 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without 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. 7.3 machined rings with flanges, without 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 & RNA-49-series range
| Bore d | 1.378 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.669 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 6 mm |
| Smallest bore in RNA-49-series | 14 mm |
| Largest outer diameter in RNA-49-series | 190 mm |
| Width range across RNA-49-series | 13–50 mm |
| Bore position in RNA-49-series (smallest first) | 9 of 28 |
| Bore above smallest RNA-49-series size | 21 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| RNA4906-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×17 mm envelope, but catalogue C/C0 differ between the executions (25.5/39 vs 23.3/32 kN) — boundary dimensions match, not a load-rating equivalent. |
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 RNA4906 model number is decoded
RNA 4906 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 35 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 35 mm Fw and 17 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 69 g at 35×47×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.
Typical equipment & failure modes
Common applications
- cam followers built up from separate components
- crank pins and eccentrics where the hardened journal is the raceway
- gearbox planetary and idler gears on hardened pins
- piston-pin style pivots in hydraulic pumps
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
- rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away
Selection pitfalls — read before you substitute
- At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.
- Hardness is load capacity: in families without an inner ring the 35 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 25.5/39 kN ratings are SKF catalogue values for this exact execution (RNA 4906); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 25.5/39 kN ratings and 69 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
How should the RNA 4906 be mounted?
Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs.
What limits the service life of a RNA 4906?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the RNA 4906?
A RNA 4906 measures 35 mm bore/Fw × 47 mm outside diameter × 17 mm width (1.378 × 1.85 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 69 g.
How is the RNA 4906 designation read?
RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 35 mm and width 17 mm, OD 47 mm comes from the dimension series, and the flanged outer ring retains the caged rollers.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring on 2026-09-26. Read our editorial & correction policy.