1311-ETN9 bearing: complete specifications & equivalents
The 1311-ETN9 is a ISO 15 radial bearing sized 55 x 120 x 29 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 | 120 mm |
| Width B | 29 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 50.7 kN |
| Basic static load rating C0 | 18 kN |
| Fatigue load limit Pu | 0.92 kN |
| Reference speed (thermal) | 11000 rpm |
| Limiting speed (mechanical) | 7500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1600 g |
| Manufacturer designation | 1311 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 & 1300-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.142 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 32.5 mm |
| Smallest bore in 1300-series | 5 mm |
| Largest outer diameter in 1300-series | 320 mm |
| Width range across 1300-series | 6–74 mm |
| Bore position in 1300-series (smallest first) | 13 of 29 |
| Bore above smallest 1300-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 1311 | 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. |
| 1311-EKTN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 55×120×29 mm envelope with catalogue ratings within 10 %; 1311 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 1311-ETN9 model number is decoded
The 13xx series is the medium/normal-section self-aligning ball bearing (ISO dimension series 03). the last two digits encode the bore: 1311 carries code 11 = 55 mm (code × 5). Envelope 55×120×29 mm (2.165×4.724×1.142 in) with a 32.5 mm radial section height, C 50.7 kN, C0 18 kN and Pu 0.92 kN. The open 1311 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 11000 r/min, limiting speed 7500 r/min, catalogue mass 1600 g.
Typical equipment & failure modes
Common applications
- textile machinery drives
- industrial fans and blowers
- woodworking machinery
- pump shafts with mild misalignment
Known failure patterns
- contamination wear when the open arrangement is used without adequate external sealing
- lubricant starvation where no regreasing interval is maintained
- excessive misalignment loading one ball row heavily and spalling it early
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- The fatigue load limit is 0.92 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The spherical outer raceway lets 1311-ETN9 tolerate shaft deflection, but it does not increase thrust capacity — combined loads still need an angular-contact or deep-groove bearing.
- The ETN9 suffix on 1311-ETN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 7500 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
- 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.
- Catalogue ratings for 1311-ETN9 (C 50.7 kN, C0 18 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
- Mount 1311-ETN9 by heating the inner ring (max 120 °C) on a cylindrical bore — driving it home through the outer ring or balls brinells the raceways.
Frequently asked questions
What are the dimensions of 1311-ETN9?
SKF 1311 ETN9 measures 55 mm bore × 120 mm OD × 29 mm width (2.165 × 4.724 × 1.142 in), mass about 1600 g. It is open, with no shields or seals.
How does the bore code in 1311 work?
The final two digits of 1311 are bore code 11, multiplied by 5 to give 55 mm.
What is the speed rating of 1311-ETN9?
SKF lists a 11000 r/min thermal reference speed and a 7500 r/min mechanical limiting speed for 1311 ETN9; real limits also depend on lubrication and fits.
How much misalignment can 1311-ETN9 tolerate?
Self-aligning ball bearings tolerate roughly 2–3° of static misalignment for open executions; sealed 2RS1 variants like 1311-ETN9 allow less (about 1°) because the seal lip binds first.
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.