RNA4902-XL bearing: complete specifications & equivalents
The RNA4902-XL is a ISO 15 radial bearing sized 20 x 28 x 13 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | FAG |
| Bore diameter d | 20 mm |
| Outer diameter D | 28 mm |
| Width B | 13 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 12 kN |
| Basic static load rating C0 | 13.6 kN |
| Fatigue load limit Pu | 2.47 kN |
| Reference speed (thermal) | 12000 rpm |
| Limiting speed (mechanical) | 21100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 21.7 g |
| Manufacturer designation | RNA4902-XL |
| Standard | ISO 15 |
| Catalog version | HR1 2026-09-25 |
| Last verified | 2026-09-30 |
Source: catalog reference (HR1 2026-09-25) · extracted 2026-09-30
Parameters extracted from the official FAG Rolling Bearings catalogue (HR1 2026-09-25); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.com.
Dimensions in inches & rna49-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 rna49-series | 14 mm |
| Largest outer diameter in rna49-series | 190 mm |
| Width range across rna49-series | 13–50 mm |
| Bore position in rna49-series (smallest first) | 3 of 28 |
| Bore above smallest rna49-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 per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| RNA4902-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×28×13 mm envelope per ISO 15; seal variant (OPEN vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
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-XL model number is decoded
envelope 20×28×13 mm: 20 mm seat is the hardened and ground shaft journal itself — there is no inner ring, with a thin 4.0 mm radial section packed with small-diameter needle rollers C is 12 kN and C0 13.6 kN at the 20 mm seat; the C/C0 ratio of 0.88 is characteristic of a needle bearing — high static rating relative to dynamic in a compact 28 mm outside diameter the fatigue load limit Cur is 2.47 kN, the limiting speed 21,100 r/min and the thermal reference speed 12,000 r/min; for small needle bearings the reference speed can exceed the kinematic limit, so the lower of the two governs the application dynamic capacity per millimetre of bore is 0.60 kN/mm and per millimetre of width 0.92 kN/mm — the reason 13 mm-wide needle bearings routinely replace much larger ball or roller positions mass is 21.7 g, just 0.06 g per mm² of projected 28×13 mm envelope, which keeps unbalanced forces low in fast-actuating linkages at 20 mm bore this size balances the 28 mm outside diameter against machineability of the adjacent parts — the most frequently specified band in the HR1 range RNA4902-XL has no inner ring: the needle rollers run directly on the shaft journal, so the seat must be hardened (58–64 HRC) and ground to bearing raceway quality This bearing accepts axial displacement between shaft and housing because the rollers rotate on the free journal; it locates nothing axially and must be flanked by guide faces As an X-life (-XL) bearing it benefits from the optimised surface finish that reduces friction and raises the fatigue strength behind the 2.47 kN Cur value. Typical applications include hydraulic and pneumatic pump eccentrics, copying and printing machine mechanisms and agricultural machine pivots and linkages, where the 28 mm outside diameter and 12 kN dynamic rating match the duty. In hydraulic and pneumatic pump eccentrics the unit fits a compact 20 mm seat, and in copying and printing machine mechanisms the 21.7 g mass keeps unbalanced forces low in fast linkages. Designers also specify it for agricultural machine pivots and linkages, relying on the 13 mm width and the published 13.6 kN static rating. Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO. Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
Typical equipment & failure modes
Common applications
- two-stroke and compressor piston pins
- agricultural machine pivots and linkages
- rocker arms and valve trains
- small electric motor accessory drives
Known failure patterns
- journal brinelling when a no-inner-ring bearing runs on a shaft hardened below 58 HRC or finished too rough
- needle skewing and jamming after momentary unloading of a flangeless (RNAO/NAO) pack
- raceway pitting from contamination drawn through the open ends of an unsealed bearing
- edge loading at the roller ends from a tapered or lobed shaft seat
- cage damage from shock loading or from pressing the bearing through the wrong ring
- lubricant starvation on fast reciprocating strokes that never fully rotate the needles
- false brinelling during stationary transport vibration
- spalling from excessive interference that removes the radial clearance
- roller wear from misaligned connecting-rod eyes and rocker bores
Selection pitfalls — read before you substitute
- Needle bearings are pure-radial units — any thrust must be taken by separate washers or an adjacent bearing, especially on flangeless RNAO/NAO.
- Without an inner ring the shaft is the raceway: 58–64 HRC and a ground, polished journal are mandatory, not recommendations.
- Do not press an RNA/NK assembly in through the outer ring when mounting it on a shaft, and vice versa — rolling forces through the wrong ring bruises the raceways.
Frequently asked questions
What are the dimensions of the RNA4902-XL?
The RNA4902-XL is a RNA49 dimension-series 49 needle roller bearing without inner ring with 28 mm outside diameter, 20 mm bore and 13 mm width, envelope 20×28×13 mm. Mass is 21.7 g.
What does the RNA4902-XL designation mean in the FAG/INA HR1 catalogue?
RNA4902-XL identifies this RNA49 dimension-series 49 needle roller bearing without inner ring in the Schaeffler HR1 rolling bearings catalogue; the -XL suffix marks the X-life execution. The envelope is 20×28×13 mm and the catalogue ratings are C 12 kN, C0 13.6 kN, Cur 2.47 kN.
What is the load capacity of the RNA4902-XL?
The basic dynamic load rating C is 12 kN and the basic static load rating C0 is 13.6 kN; the fatigue load limit Cur is 2.47 kN.
What is the maximum speed of the RNA4902-XL?
The limiting speed is 21,100 r/min and the thermal reference speed is 12,000 r/min. In the Schaeffler catalogue the reference speed is the thermally permissible running speed under defined load; the lower of the two values governs each application.
Can the RNA4902-XL run directly on an ordinary shaft?
Not on a soft shaft. The RNA4902-XL has no inner ring, so the 20 mm journal itself is the raceway: harden it to 58–64 HRC and finish-grind to the catalogue journal tolerance. Where the shaft cannot be hardened, use the corresponding with-inner-ring execution instead.
Reviewed & verified by the MPN Base engineering desk against source catalog HR1 2026-09-25 on 2026-09-30. Read our editorial & correction policy.