1203-ETN9 bearing: complete specifications & equivalents
The 1203-ETN9 is a ISO 15 radial bearing sized 17 x 40 x 12 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 40 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 8.84 kN |
| Basic static load rating C0 | 2.2 kN |
| Fatigue load limit Pu | 0.12 kN |
| Reference speed (thermal) | 38000 rpm |
| Limiting speed (mechanical) | 24000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 73 g |
| Manufacturer designation | 1203 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.575 in |
| Width B | 0.472 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 11.5 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) | 8 of 32 |
| Bore above smallest 1200-series size | 11 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 1203 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 1203-ETN9 model number is decoded
The 12xx series is the light/normal-section self-aligning ball bearing (ISO dimension series 02). bore code 03 follows the 10/12/15/17 mm exception table, so 1203 fits a 17 mm shaft. Envelope 17×40×12 mm (0.669×1.575×0.472 in) with a 11.5 mm radial section height, C 8.84 kN, C0 2.2 kN and Pu 0.12 kN. The open 1203 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 17 mm shaft. Reference (thermal) speed 38000 r/min, limiting speed 24000 r/min, catalogue mass 73 g.
Typical equipment & failure modes
Common applications
- food-processing conveyors
- small electric motors
- conveyor idler rollers
- agricultural machinery shafts
Known failure patterns
- contamination wear when the open arrangement is used without adequate external sealing
- lubricant starvation where no regreasing interval is maintained
- fretting corrosion on a creeping shaft or housing seat
- cage damage from running beyond the limiting speed
Selection pitfalls — read before you substitute
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 1203-ETN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- Catalogue ratings for 1203-ETN9 (C 8.84 kN, C0 2.2 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.
- The ETN9 suffix on 1203-ETN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 24000 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 17 mm rotating shaft use a j5/k5 seat with an H7 housing; reverse the logic if the outer ring rotates.
- Catalogue ratings for 1203-ETN9 (C 8.84 kN, C0 2.2 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 1203-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 1203-ETN9?
SKF 1203 ETN9 measures 17 mm bore × 40 mm OD × 12 mm width (0.669 × 1.575 × 0.472 in), mass about 73 g. It is open, with no shields or seals.
How does the bore code in 1203 work?
Codes 00–03 follow the exception table (10, 12, 15, 17 mm): 1203 fits a 17 mm shaft. Code × 5 starts at code 04.
What is the speed rating of 1203-ETN9?
SKF lists a 38000 r/min thermal reference speed and a 24000 r/min mechanical limiting speed for 1203 ETN9; real limits also depend on lubrication and fits.
How much misalignment can 1203-ETN9 tolerate?
Self-aligning ball bearings tolerate roughly 2–3° of static misalignment for open executions; sealed 2RS1 variants like 1203-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.