1309-ETN9 bearing: complete specifications & equivalents
The 1309-ETN9 is a ISO 15 radial bearing sized 45 x 100 x 25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 100 mm |
| Width B | 25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 39 kN |
| Basic static load rating C0 | 13.4 kN |
| Fatigue load limit Pu | 0.7 kN |
| Reference speed (thermal) | 12000 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 960 g |
| Manufacturer designation | 1309 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 | 1.772 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.984 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 27.5 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) | 11 of 29 |
| Bore above smallest 1300-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 1309 | 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. |
| 1309-EKTN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 45×100×25 mm envelope with catalogue ratings within 10 %; 1309 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 1309-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: 1309 carries code 09 = 45 mm (code × 5). Envelope 45×100×25 mm (1.772×3.937×0.984 in) with a 27.5 mm radial section height, C 39 kN, C0 13.4 kN and Pu 0.7 kN. The open 1309 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 45 mm shaft. Reference (thermal) speed 12000 r/min, limiting speed 8500 r/min, catalogue mass 960 g.
Typical equipment & failure modes
Common applications
- industrial fans and blowers
- woodworking machinery
- pump shafts with mild misalignment
- material-handling equipment
Known failure patterns
- lubricant starvation where no regreasing interval is maintained
- contamination wear when the open arrangement is used without adequate external sealing
- electrical pitting in VFD-driven motors without shaft grounding
- excessive misalignment loading one ball row heavily and spalling it early
Selection pitfalls — read before you substitute
- Mount 1309-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.
- Fillet radii must clear the 1309-ETN9 chamfer so the 25 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- The ETN9 suffix on 1309-ETN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 8500 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
- Catalogue ratings for 1309-ETN9 (C 39 kN, C0 13.4 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 1309-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.
- The fatigue load limit is 0.7 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
Frequently asked questions
What are the dimensions of 1309-ETN9?
SKF 1309 ETN9 measures 45 mm bore × 100 mm OD × 25 mm width (1.772 × 3.937 × 0.984 in), mass about 960 g. It is open, with no shields or seals.
How does the bore code in 1309 work?
The final two digits of 1309 are bore code 09, multiplied by 5 to give 45 mm.
How much misalignment can 1309-ETN9 tolerate?
Self-aligning ball bearings tolerate roughly 2–3° of static misalignment for open executions; sealed 2RS1 variants like 1309-ETN9 allow less (about 1°) because the seal lip binds first.
Can 1309-ETN9 take axial load?
A self-aligning ball bearing can carry some axial load in addition to radial load, but its axial capacity is lower than an angular-contact bearing of the same envelope. Use it where misalignment, not thrust, is the main requirement.
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.