RNA4906-2RS bearing: complete specifications & equivalents
The RNA4906-2RS is a ISO 1206 radial bearing sized 35 x 47 x 17 mm (bore x OD x width) with 2RS sealing. 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 | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 23.3 kN |
| Basic static load rating C0 | 32 kN |
| Fatigue load limit Pu | 3.8 kN |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 69 g |
| Manufacturer designation | RNA 4906.2RS |
| 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 | 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 (23.3/32 vs 25.5/39 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 RNA4906-2RS model number is decoded
RNA 4906.2RS is a ribbed machined-ring needle roller bearing (no inner ring) sized 35×47×17 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 35 mm shaft journal completes the bearing. 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. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.
Typical equipment & failure modes
Common applications
- swing arms and lever pivots with oscillating duty
- 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
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
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- electrical erosion on VFD-driven shafts without brush or insulated mounting
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
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.
- Do not interchange envelope-identical needle families blindly: RNA 4906.2RS shares its 35×47×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.
- The 23.3/32 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
What limits the service life of a RNA 4906.2RS?
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 4906.2RS?
A RNA 4906.2RS 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 23.3 kN, static C0 32 kN, fatigue limit Pu 3.8 kN, limiting speed 5,600 r/min, mass about 69 g.
How is the RNA 4906.2RS 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.
Can the RNA 4906.2RS run on an unhardened shaft?
No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead.
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.