RNA6906 bearing: complete specifications & equivalents
The RNA6906 is a ISO 1206 radial bearing sized 35 x 47 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 | 35 mm |
| Outer diameter D | 47 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 42.9 kN |
| Basic static load rating C0 | 75 kN |
| Fatigue load limit Pu | 9.3 kN |
| Reference speed (thermal) | 11000 rpm |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 130 g |
| Manufacturer designation | RNA 6906 |
| 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-69-series range
| Bore d | 1.378 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 1.181 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 6 mm |
| Smallest bore in RNA-69-series | 16 mm |
| Largest outer diameter in RNA-69-series | 130 mm |
| Width range across RNA-69-series | 22–63 mm |
| Bore position in RNA-69-series (smallest first) | 8 of 22 |
| Bore above smallest RNA-69-series size | 19 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NX35-Z | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent. |
| NX35 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent. |
| NKX35-Z | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent. |
| NKX35 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent. |
| NKXR35 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent. |
| NKXR35-Z | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 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 RNA6906 model number is decoded
Where the shaft can be hardened and ground, SKF offers RNA 6906 in the dimension series 69 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 35 mm bore seat and 47 mm OD. Reading the designation: RNA gives the series and the numbers the boundary plan — 35 mm Fw for the shaft seat, 30 mm width; the 47 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 42.9/75 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. 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
- guide rollers running on hardened tracks
- 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
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
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- rolling-contact fatigue spalling after the rated L10 life
- 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.
- 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 6906 shares its 35×47×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- The 42.9/75 kN ratings and 130 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
Does the RNA 6906 need a hardened and ground 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.
What mounting mistakes ruin a RNA 6906?
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.
Is the RNA 6906 sealed?
No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty.
Which dimensions does the RNA 6906 have?
A RNA 6906 measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 75 kN, fatigue limit Pu 9.3 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 130 g.
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.