RNA4902-2RS bearing: complete specifications & equivalents
The RNA4902-2RS is a ISO 1206 radial bearing sized 20 x 28 x 13 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 | 20 mm |
| Outer diameter D | 28 mm |
| Width B | 13 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 9.13 kN |
| Basic static load rating C0 | 12 kN |
| Fatigue load limit Pu | 1.43 kN |
| Limiting speed (mechanical) | 9500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 22 g |
| Manufacturer designation | RNA 4902.2RS |
| 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 | 0.787 in |
|---|---|
| Outer diameter D | 1.102 in |
| Width B | 0.512 in |
| ISO bore code | 02 |
| Radial section height (D−d)/2 | 4 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) | 3 of 28 |
| Bore above smallest RNA-49-series size | 6 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| RNA4902 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×28×13 mm envelope, but catalogue C/C0 differ between the executions (9.13/12 vs 11.2/15.3 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 RNA4902-2RS model number is decoded
SKF's dimension series 49 needle roller bearings without inner ring include RNA 4902.2RS: 20 mm Fw, 28 mm outside diameter, 13 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 20 mm under-roller diameter and the 13 mm width, with the 28 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. 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. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 9,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 20 mm seat. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 28 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.
Typical equipment & failure modes
Common applications
- gearbox planetary and idler gears on hardened pins
- piston-pin style pivots in hydraulic pumps
- guide rollers running on hardened tracks
- swing arms and lever pivots with oscillating duty
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- 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
- false brinelling of standby equipment under external vibration
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
Selection pitfalls — read before you substitute
- On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- 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.
- Do not interchange envelope-identical needle families blindly: RNA 4902.2RS shares its 20×28×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- The 9.13/12 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Which dimensions does the RNA 4902.2RS have?
A RNA 4902.2RS measures 20 mm bore/Fw × 28 mm outside diameter × 13 mm width (0.787 × 1.102 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12 kN, fatigue limit Pu 1.43 kN, limiting speed 9,500 r/min, mass about 22 g.
What does RNA 4902.2RS mean in SKF part numbering?
RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 20 mm and width 13 mm, OD 28 mm comes from the dimension series, and the flanged outer ring retains the caged rollers.
Does the RNA 4902.2RS need a hardened and ground shaft?
No. In this execution the 20 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.
What mounting mistakes ruin a RNA 4902.2RS?
Press on the ring faces only with a fitting sleeve, keep everything square to the 20 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.
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.