RNA6912 bearing: complete specifications & equivalents
The RNA6912 is a ISO 1206 radial bearing sized 68 x 85 x 45 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 68 mm |
| Outer diameter D | 85 mm |
| Width B | 45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 93.5 kN |
| Basic static load rating C0 | 204 kN |
| Fatigue load limit Pu | 25 kN |
| Reference speed (thermal) | 6000 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 490 g |
| Manufacturer designation | RNA 6912 |
| 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 | 2.677 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 1.772 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 8.5 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) | 15 of 22 |
| Bore above smallest RNA-69-series size | 52 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the RNA6912 model number is decoded
RNA 6912 belongs to the machined-ring needle roller family: an outer ring turned and ground to 85 mm with two retaining flanges, a roller-and-cage set inside, and envelope 68×85×45 mm on a hardened 68 mm shaft. The RNA 6912 code states Fw 68 and width 45 mm directly; because the family has no inner ring, the 68 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. 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 93.5/204 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. 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
- 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
- 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
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- hard-particle indentation in unfiltered lubricant
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
Selection pitfalls — read before you substitute
- Above 50 mm bore, thermal growth matters: the 68 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.
- Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.
- 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.
- The 93.5/204 kN ratings and 490 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
How should the RNA 6912 be mounted?
Press on the ring faces only with a fitting sleeve, keep everything square to the 68 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 6912?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 68 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the RNA 6912?
A RNA 6912 measures 68 mm bore/Fw × 85 mm outside diameter × 45 mm width (2.677 × 3.346 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 93.5 kN, static C0 204 kN, fatigue limit Pu 25 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 490 g.
How is the RNA 6912 designation read?
RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 68 mm and width 45 mm, OD 85 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.