1309-EKTN9 bearing: complete specifications & equivalents
The 1309-EKTN9 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 EKTN9 |
| 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-ETN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 45×100×25 mm envelope with catalogue ratings within 10 %; 1309 ETN9 is the glass-fibre PA66 cage, open arrangement 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-EKTN9 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 EKTN9 carries no shields or seals and relies on application lubrication and external sealing. The EKTN9 suffix identifies the glass-fibre-reinforced polyamide 66 cage execution. The K suffix marks a 1:12 tapered bore for direct mounting on a tapered shaft or with an adapter sleeve. Reference (thermal) speed 12000 r/min, limiting speed 8500 r/min, catalogue mass 960 g.
Typical equipment & failure modes
Common applications
- conveyor drum and pulley shafts
- agricultural gearboxes
- textile machinery drives
- industrial fans and blowers
Known failure patterns
- contamination wear when the open arrangement is used without adequate external sealing
- lubricant starvation where no regreasing interval is maintained
- adapter-sleeve fretting when the sleeve is not locked against the shaft shoulder
- incorrect sleeve tightening that leaves the tapered bore loose or over-expanded, changing internal clearance
- 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 0.7 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- 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.
- The K suffix means a 1:12 tapered bore: 1309-EKTN9 is not a drop-in for the straight-bore version — it needs a tapered shaft or an H-series adapter sleeve.
- The EKTN9 suffix on 1309-EKTN9 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.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 1309-EKTN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- Assign interference to the rotating ring: on a 45 mm rotating shaft use a k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
Frequently asked questions
What are the dimensions of 1309-EKTN9?
SKF 1309 EKTN9 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 heavy is 1309-EKTN9?
Catalogue mass is 960 g for 1309 EKTN9; seal and cage executions of the same envelope differ by a few grams.
What load can 1309-EKTN9 take?
Catalogue values for 1309 EKTN9: dynamic C 39 kN, static C0 13.4 kN, fatigue limit Pu 0.7 kN. Use C in life calculation and C0 for static checks at 45 mm bore.
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.