2301 bearing: complete specifications & equivalents
The 2301 is a ISO 15 radial bearing sized 12 x 37 x 17 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 12 mm |
| Outer diameter D | 37 mm |
| Width B | 17 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 12.1 kN |
| Basic static load rating C0 | 2.73 kN |
| Fatigue load limit Pu | 0.12 kN |
| Limiting speed (mechanical) | 17000 rpm |
| Mass | 87 g |
| Manufacturer designation | 2301S |
| Standard | ISO 15 |
| Catalog version | CAT. No. 2203-3/E 2024 |
| Last verified | 2026-09-25 |
Source: catalog reference (CAT. No. 2203-3/E 2024) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (CAT. No. 2203-3/E 2024); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & 2300-series range
| Bore d | 0.472 in |
|---|---|
| Outer diameter D | 1.457 in |
| Width B | 0.669 in |
| ISO bore code | 01 |
| Radial section height (D−d)/2 | 12.5 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) | 2 of 21 |
| Bore above smallest 2300-series size | 2 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 2301 model number is decoded
In the 2300-series (ISO 15 dimension series) the leading digits 23 mark a double-row self-aligning ball bearing and the last two digits encode the bore: 2301 carries bore code 01 = 12 mm. Codes 00–03 follow the 10/12/15/17 mm exception table rather than code × 5. Outside diameter 37 mm and width 17 mm follow the ISO 15 general plan. The cylindrical bore fits directly on a machined shaft seat; a tapered-bore K variant is available for adapter-sleeve mounting. Two rows of balls run on a common sphered outer raceway, allowing the inner ring to pivot and compensate for shaft deflection or housing misalignment.
Typical equipment & failure modes
Common applications
- domestic appliance drive shafts
- power tool spindles
- small pump impeller shafts
- garden equipment and light machinery
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- raceway smearing under marginal lubrication at start-up
- fretting corrosion on a loose shaft seat
Selection pitfalls — read before you substitute
- Bore codes 00–03 use the exception table: 2301 fits a 12 mm shaft — the code × 5 mnemonic does not apply below code 04 (it would imply 0 mm for code 00).
- The 23xx heavy wide-section at 12 mm bore is built for high-load, lower-speed duty; specifying it in a high-rpm application gives excess heat and short grease life — use 12/13 there.
- The open 2301 has no lubricant retention: grease escapes and contaminants migrate straight into the 12×37×17 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 2300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 2301 units.
- Suffixes stack in a defined order — clearance follows the bore code, e.g. 2301-C3. No clearance suffix means normal CN clearance.
Frequently asked questions
What are the dimensions of a 2301 self-aligning ball bearing?
A 2301 self-aligning ball bearing has a 12 mm bore, 37 mm outer diameter and 17 mm width, per ISO 15 boundary dimensions. This is the cylindrical-bore version; a tapered-bore K variant is available for adapter-sleeve mounting.
Why does 2301 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 2301 with code 01 has a 12 mm bore. The code × 5 convention starts at code 04 (20 mm).
What does the open suffix mean on 2301?
A bare 2301 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 2300 compare with other self-aligning series at the same 12 mm bore?
The 23xx is the wide heavy section: 37×17 mm, 12.5 mm radial section at 12 mm bore — the highest-capacity double-row self-aligning option here, aimed at lower-speed, high-load shafts.
Reviewed & verified by the MPN Base engineering desk against source catalog CAT. No. 2203-3/E 2024 on 2026-09-25. Read our editorial & correction policy.