Reference & Charts
Ball Bearing Sizes
Boundary dimensions for common deep-groove ball bearings (608, 6000, 6200, 6300 series and more): bore, outside diameter, and width in millimetres, with a spec sheet per bearing. Cross-reference a bearing number to its size, or a shaft size to the bearings that fit.
20 entries · Last verified: 2026-07-10
Deep-groove ball bearings are numbered so the digits encode the size. The last two digits give the bore for bearings 04 and up (multiply by 5 — so 6204 is 20 mm bore); 00, 01, 02, 03 mean 10, 12, 15, 17 mm. The first digits set the series — 6000 (extra light), 6200 (light), 6300 (medium) — which fixes the OD and width for that bore. A larger series at the same bore means a bigger, higher-capacity bearing. Bore, OD, and width are standardized by ISO 15, so a 6204 from any maker interchanges.
| Bearing | Series | Bore(mm) | OD(mm) | Width(mm) |
|---|---|---|---|---|
| 625 | 62 (miniature) | 5 mm | 16 mm | 5 mm |
| 608 | 60 (miniature) | 8 mm | 22 mm | 7 mm |
| 6000 | 6000 (extra light) | 10 mm | 26 mm | 8 mm |
| 6001 | 6000 (extra light) | 12 mm | 28 mm | 8 mm |
| 6002 | 6000 (extra light) | 15 mm | 32 mm | 9 mm |
| 6003 | 6000 (extra light) | 17 mm | 35 mm | 10 mm |
| 6004 | 6000 (extra light) | 20 mm | 42 mm | 12 mm |
| 6005 | 6000 (extra light) | 25 mm | 47 mm | 12 mm |
| 6200 | 6200 (light) | 10 mm | 30 mm | 9 mm |
| 6201 | 6200 (light) | 12 mm | 32 mm | 10 mm |
| 6202 | 6200 (light) | 15 mm | 35 mm | 11 mm |
| 6203 | 6200 (light) | 17 mm | 40 mm | 12 mm |
| 6204 | 6200 (light) | 20 mm | 47 mm | 14 mm |
| 6205 | 6200 (light) | 25 mm | 52 mm | 15 mm |
| 6300 | 6300 (medium) | 10 mm | 35 mm | 11 mm |
| 6301 | 6300 (medium) | 12 mm | 37 mm | 12 mm |
| 6302 | 6300 (medium) | 15 mm | 42 mm | 13 mm |
| 6303 | 6300 (medium) | 17 mm | 47 mm | 14 mm |
| 6304 | 6300 (medium) | 20 mm | 52 mm | 15 mm |
| 6305 | 6300 (medium) | 25 mm | 62 mm | 17 mm |
Select a bearing for its full spec sheet.
Frequently asked
- How do I read a bearing number like 6204?
- The '62' is the series (6200, light). The last two digits '04' give the bore: for 04 and up, multiply by 5 — so 6204 has a 20 mm bore. (00 = 10 mm, 01 = 12 mm, 02 = 15 mm, 03 = 17 mm.) The series then sets the OD and width — a 6204 is 20 × 47 × 14 mm.
- What's the difference between a 6204 and a 6304?
- Same 20 mm bore, different series. The 6304 (6300 medium series) has a larger OD and width (52 × 15 mm vs. the 6204's 47 × 14 mm), so it carries more load — at the cost of more space and usually a lower speed limit.
- Does this include load ratings?
- No — bore, OD, and width are standardized and interchangeable, but dynamic/static load ratings and speed limits vary by manufacturer and internal design. Read those from the specific bearing maker's datasheet.
Sources
- ISO 15 — rolling bearings, radial bearings, boundary dimensions (metric size plan)