1211-ETN9 bearing: complete specifications & equivalents
The 1211-ETN9 is a ISO 15 radial bearing sized 55 x 100 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 55 mm |
| Outer diameter D | 100 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 27.6 kN |
| Basic static load rating C0 | 10.6 kN |
| Fatigue load limit Pu | 0.54 kN |
| Reference speed (thermal) | 14000 rpm |
| Limiting speed (mechanical) | 9000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 710 g |
| Manufacturer designation | 1211 ETN9 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); 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 & 1200-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.827 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in 1200-series | 6 mm |
| Largest outer diameter in 1200-series | 230 mm |
| Width range across 1200-series | 6–154 mm |
| Bore position in 1200-series (smallest first) | 17 of 32 |
| Bore above smallest 1200-series size | 49 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 1211 | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 1211-EKTN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 55×100×21 mm envelope with catalogue ratings within 10 %; 1211 EKTN9 is the glass-fibre PA66 cage, open arrangement, tapered bore execution of this size — boundary dimensions interchangeable, only the seal/cage/bore execution differs. |
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 1211-ETN9 model number is decoded
The 12xx series is the light/normal-section self-aligning ball bearing (ISO dimension series 02). the last two digits encode the bore: 1211 carries code 11 = 55 mm (code × 5). Envelope 55×100×21 mm (2.165×3.937×0.827 in) with a 22.5 mm radial section height, C 27.6 kN, C0 10.6 kN and Pu 0.54 kN. The open 1211 ETN9 carries no shields or seals and relies on application lubrication and external sealing. The ETN9 suffix identifies the glass-fibre-reinforced polyamide 66 cage execution. The bore is cylindrical (straight), for a press-fit on a 55 mm shaft. Reference (thermal) speed 14000 r/min, limiting speed 9000 r/min, catalogue mass 710 g.
Typical equipment & failure modes
Common applications
- pump shafts with mild misalignment
- material-handling equipment
- industrial electric motors
- conveyor drum and pulley shafts
Known failure patterns
- lubricant starvation where no regreasing interval is maintained
- contamination wear when the open arrangement is used without adequate external sealing
- cage damage from running beyond the limiting speed
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Assign interference to the rotating ring: on a 55 mm rotating shaft use a k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
- Assign interference to the rotating ring: on a 55 mm rotating shaft use a k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
- The ETN9 suffix on 1211-ETN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 9000 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
- The fatigue load limit is 0.54 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- At 55 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
- The spherical outer raceway lets 1211-ETN9 tolerate shaft deflection, but it does not increase thrust capacity — combined loads still need an angular-contact or deep-groove bearing.
Frequently asked questions
What are the dimensions of 1211-ETN9?
SKF 1211 ETN9 measures 55 mm bore × 100 mm OD × 21 mm width (2.165 × 3.937 × 0.827 in), mass about 710 g. It is open, with no shields or seals.
How does the bore code in 1211 work?
The final two digits of 1211 are bore code 11, multiplied by 5 to give 55 mm.
What load can 1211-ETN9 take?
Catalogue values for 1211 ETN9: dynamic C 27.6 kN, static C0 10.6 kN, fatigue limit Pu 0.54 kN. Use C in life calculation and C0 for static checks at 55 mm bore.
What is the speed rating of 1211-ETN9?
SKF lists a 14000 r/min thermal reference speed and a 9000 r/min mechanical limiting speed for 1211 ETN9; real limits also depend on lubrication and fits.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.