1204-EKTN9 bearing: complete specifications & equivalents
The 1204-EKTN9 is a ISO 15 radial bearing sized 20 x 47 x 14 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 20 mm |
| Outer diameter D | 47 mm |
| Width B | 14 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 12.7 kN |
| Basic static load rating C0 | 3.4 kN |
| Fatigue load limit Pu | 0.18 kN |
| Reference speed (thermal) | 32000 rpm |
| Limiting speed (mechanical) | 20000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 120 g |
| Manufacturer designation | 1204 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 & 1200-series range
| Bore d | 0.787 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.551 in |
| ISO bore code | 04 |
| Radial section height (D−d)/2 | 13.5 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) | 9 of 32 |
| Bore above smallest 1200-series size | 14 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 1204 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 1204-ETN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×14 mm envelope with catalogue ratings within 10 %; 1204 ETN9 is the glass-fibre PA66 cage, open arrangement execution of this size — boundary dimensions interchangeable, only the seal/cage/bore execution differs. |
| 11204-ETN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×14 mm envelope with catalogue ratings within 10 %; 11204 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 1204-EKTN9 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: 1204 carries code 04 = 20 mm (code × 5). Envelope 20×47×14 mm (0.787×1.85×0.551 in) with a 13.5 mm radial section height, C 12.7 kN, C0 3.4 kN and Pu 0.18 kN. The open 1204 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 32000 r/min, limiting speed 20000 r/min, catalogue mass 120 g.
Typical equipment & failure modes
Common applications
- woodworking machine spindles
- light gearbox layshafts
- food-processing conveyors
- small electric motors
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
- 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 1204-EKTN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- Self-aligning ball bearings tolerate up to roughly 2–3° of static misalignment, but the sealed 1204-EKTN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
- Tighten the adapter sleeve to the SKF-recommended starting clearance, not to feel — an over-tightened sleeve expands the inner ring and removes all internal clearance.
- The EKTN9 suffix on 1204-EKTN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 20000 r/min limiting speed, but it softens above roughly 120 °C — check the oil temperature in hot drives.
- The fatigue load limit is 0.18 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- At 20 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.
Frequently asked questions
What are the dimensions of 1204-EKTN9?
SKF 1204 EKTN9 measures 20 mm bore × 47 mm OD × 14 mm width (0.787 × 1.85 × 0.551 in), mass about 120 g. It is open, with no shields or seals.
How does the bore code in 1204 work?
The final two digits of 1204 are bore code 04, multiplied by 5 to give 20 mm.
Can 1204-EKTN9 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.
Which fits should I use for 1204-EKTN9?
With a rotating inner ring use roughly k5 on the shaft and H7 in the 47 mm housing; reverse the interference if the outer ring rotates.
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.