Self-aligning ball bearing · 23 series (wide)
2304 bearing
20 × 52 × 21 mm
The 2304 is a self-aligning ball bearing with a 20 mm bore, 52 mm outside diameter and 21 mm width. Wider version of the 13 series.
- Bore d
- 20 mm 0.7874 in
- Outside diameter D
- 52 mm 2.0472 in
- Width B
- 21 mm 0.8268 in
- Dimension series
- 23
- Load directions
- Mainly radial; light axial
Designation explained
What 2304 means
Standard bearing numbers encode the type, the dimension series and the bore. Anything after the base number — seals, clearance, cage — is a suffix.
| Part | Meaning |
|---|---|
23 | Wide self-aligning ball bearing, dimension series 23 (the type digit 1 is omitted by convention) |
04 | 04 → 20 mm bore (04 × 5) |
Variants
Common 2304 variants
Suffixes change the bearing without changing its boundary dimensions. The exact letters differ between manufacturers — always order by the full designation from the maker you choose.
| Suffix | Example | Meaning |
|---|---|---|
K | 2304K | Tapered bore (taper 1:12) for mounting on an adapter or withdrawal sleeve |
2RS | 2304-2RS | Contact seals on both sides (available for selected sizes; may be wider) |
TV / TN9 / M | 2304-TVH | Cage material: polyamide (TV, TN9) or machined brass (M) — letters vary by maker |
CN (no suffix) | 2304 | Normal internal clearance |
C3 | 2304-C3 | Internal clearance greater than normal — common for electric motors and heated shafts |
C4 | 2304-C4 | Internal clearance greater than C3 |
Same envelope
Same 20 × 52 × 21 mm, different type
These bearings have exactly the same bore, outside diameter and width but are a different type. They fit the same housing and shaft, but carry loads differently — same size is not the same function.
| Designation | Type | Dimensions |
|---|---|---|
| NU2304 | Cylindrical roller bearing | 20 × 52 × 21 mm |
Same bore
Other 20 mm bore bearings
Every standard bearing in this reference with a 20 mm bore, from light to heavy sections.
| Designation | Type | D | B / H |
|---|---|---|---|
| 6004 | Deep groove ball bearing | 42 mm | 12 mm |
| 6204 | Deep groove ball bearing | 47 mm | 14 mm |
| 6304 | Deep groove ball bearing | 52 mm | 15 mm |
| 6404 | Deep groove ball bearing | 72 mm | 19 mm |
| 61804 | Deep groove ball bearing | 32 mm | 7 mm |
| 61904 | Deep groove ball bearing | 37 mm | 9 mm |
| 16004 | Deep groove ball bearing | 42 mm | 8 mm |
| 1204 | Self-aligning ball bearing | 47 mm | 14 mm |
| 1304 | Self-aligning ball bearing | 52 mm | 15 mm |
| 2204 | Self-aligning ball bearing | 47 mm | 18 mm |
| 7204 | Angular contact ball bearing | 47 mm | 14 mm |
| 7304 | Angular contact ball bearing | 52 mm | 15 mm |
| NU204 | Cylindrical roller bearing | 47 mm | 14 mm |
| NU304 | Cylindrical roller bearing | 52 mm | 15 mm |
| NU2204 | Cylindrical roller bearing | 47 mm | 18 mm |
| 30204 | Tapered roller bearing | 47 mm | 15.25 mm |
| 30304 | Tapered roller bearing | 52 mm | 16.25 mm |
| 32004X | Tapered roller bearing | 42 mm | 15 mm |
| 32204 | Tapered roller bearing | 47 mm | 19.25 mm |
| 32304 | Tapered roller bearing | 52 mm | 22.25 mm |
| 51104 | Thrust ball bearing | 35 mm | 10 mm |
| 51204 | Thrust ball bearing | 40 mm | 14 mm |
| UCP204 | Pillow block bearing unit | — | — |
Where to buy
Find 2304 at sellers
Search results on independent sellers. We are not affiliated with them, do not earn from these links and do not see their prices or stock. Results mix brands and variants — check the full designation before you order.
About these dimensions. Boundary dimensions follow ISO 15 (radial bearings — boundary dimensions, general plan), dimension series 23, and are the same for every manufacturer of a standard 2304. Chamfers, load ratings, speed limits and weight depend on the manufacturer and design and are not shown — use the maker's datasheet for engineering decisions. Last checked 9 October 2026. Spotted an error? Tell us.
Learn more
What size is a 2304 bearing?
A 2304 is a self-aligning ball bearing with a 20 mm bore, 52 mm outside diameter and 21 mm width (20 × 52 × 21 mm). These boundary dimensions follow the ISO dimension plan, so they are the same across manufacturers.
Can I replace 2304 with another bearing of the same size?
Other bearing types can share the same 20 × 52 × 21 mm envelope, but a different type has different load directions, speed limits and mounting needs. Same dimensions alone do not make two bearings interchangeable.
Where are the load ratings and speed limits?
They depend on the manufacturer and internal design, so we do not list a single value. Check the datasheet for the exact full designation you intend to use.
Need 2304 data for a whole catalog?
We can help with that.
Normalized specifications, variants and supplier listings for every bearing you sell, with the source behind each value.