2308-E-2RS1KTN9 bearing: complete specifications & equivalents
The 2308-E-2RS1KTN9 is a ISO 15 radial bearing sized 40 x 90 x 33 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 40 mm |
| Outer diameter D | 90 mm |
| Width B | 33 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 33.8 kN |
| Basic static load rating C0 | 11.2 kN |
| Fatigue load limit Pu | 0.57 kN |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 960 g |
| Manufacturer designation | 2308 E-2RS1KTN9 |
| 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 & 2300-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 1.299 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 2300-series | 10 mm |
| Largest outer diameter in 2300-series | 215 mm |
| Width range across 2300-series | 17–73 mm |
| Bore position in 2300-series (smallest first) | 9 of 21 |
| Bore above smallest 2300-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 2308 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×33 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 2308-E-2RS1TN9 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 40×90×33 mm envelope with catalogue ratings within 10 %; 2308 E-2RS1TN9 is the glass-fibre PA66 cage, two contact elastomer seals execution of this size — boundary dimensions interchangeable, only the seal/cage/bore execution differs. |
| 2308-ETN9 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×33 mm envelope, but catalogue C/C0 differ between executions (33.8/11.2 kN vs 54/16 kN) — boundary dimensions match, not a load-rating equivalent. |
| 2308-EKTN9 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×33 mm envelope, but catalogue C/C0 differ between executions (33.8/11.2 kN vs 54/16 kN) — boundary dimensions match, not a load-rating equivalent. |
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 2308-E-2RS1KTN9 model number is decoded
The 23xx series is the wide medium-section self-aligning ball bearing (ISO dimension series 23). the last two digits encode the bore: 2308 carries code 08 = 40 mm (code × 5). Envelope 40×90×33 mm (1.575×3.543×1.299 in) with a 25.0 mm radial section height, C 33.8 kN, C0 11.2 kN and Pu 0.57 kN. SKF spells the sealed execution 2308 E-2RS1KTN9 (suffix 2RS1): two contact elastomer lips over a lifetime grease fill; the lips add drag, and no thermal reference speed is published. The E-2RS1KTN9 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. Limiting speed 5000 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
- contact-seal lip hardening and grease-life expiry after long high-temperature service
- fine dust or moisture passing a worn seal lip in dirty or wet duty
- incorrect sleeve tightening that leaves the tapered bore loose or over-expanded, changing internal clearance
- adapter-sleeve fretting when the sleeve is not locked against the shaft shoulder
- 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 2308-E-2RS1KTN9 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 2308-E-2RS1KTN9 chamfer so the 33 mm-wide ring seats square; an oversized shaft radius creates point contact on the ring face.
- Do not wash 2308-E-2RS1KTN9 with solvent — the lifetime grease fill is sealed in, and solvent destroys the grease without a way to repack it.
- On a sleeve-mounted 2308-E-2RS1KTN9, lock the sleeve against the shaft shoulder; a loose sleeve creeps and frets both the shaft and the bore.
- The E-2RS1KTN9 suffix on 2308-E-2RS1KTN9 denotes a glass-fibre-reinforced polyamide 66 cage: quiet and light at the 5000 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 2308-E-2RS1KTN9 (2RS1) allows less — the lip seal binds before the spherical raceway does.
Frequently asked questions
What are the dimensions of 2308-E-2RS1KTN9?
SKF 2308 E-2RS1KTN9 measures 40 mm bore × 90 mm OD × 33 mm width (1.575 × 3.543 × 1.299 in), mass about 960 g. It has two contact rubber seals (2RS1) and a lifetime grease fill.
How does the bore code in 2308 work?
The final two digits of 2308 are bore code 08, multiplied by 5 to give 40 mm.
Which fits should I use for 2308-E-2RS1KTN9?
With a rotating inner ring use roughly k5 on the shaft and H7 in the 90 mm housing; reverse the interference if the outer ring rotates.
How heavy is 2308-E-2RS1KTN9?
Catalogue mass is 960 g for 2308 E-2RS1KTN9; seal and cage executions of the same envelope differ by a few grams.
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.