Deep groove ball bearing
6311 Bearing Dimensions
6311 deep groove ball bearing: bore 55 mm, dimensions 55x120x29 mm (ISO 15). Open, ZZ and 2RS variants, designation breakdown and size-equivalent codes.
6311 specifications
| Bore d | 55 mm |
|---|---|
| Outside diameter D | 120 mm |
| Width B | 29 mm |
| Seal / shield options | Open; ZZ (two metal shields); 2RS (two rubber seals) |
| Material | GCr15 chrome bearing steel (rings and rolling elements) |
| Precision | P0 (standard); P6 on request |
| Radial clearance | C0 (standard); C3 on request |
| Load ratings | Load ratings available on request for the specific batch and manufacturer. |
How to read the 6311 designation
| Segment | Meaning |
|---|---|
| 6 | Single row deep groove ball bearing |
| 3 | Dimension series 03 (medium) |
| 11 | Bore code 11 → 55 mm bore. ISO bore code (00–03 = 10/12/15/17 mm; 04 and above = code × 5 mm). |
6311 interchange by brand
6311 is an ISO designation. The boundary dimensions are identical across manufacturers; only suffixes (seals, clearance, cage) differ.
| SKF | NSK | NTN | FAG | Timken | Note |
|---|---|---|---|---|---|
| 6311 | 6311 | 6311 | 6311 | 6311 | Same ISO designation |
Typical applications
- Electric motors
- Fans and blowers
- Water pumps
- Gearboxes
- Agricultural and textile machinery
FAQ
Is 6311 the same size across brands?
Yes. 6311 is an ISO designation, so the bore, outside diameter and width are the same whichever manufacturer made it. Brand-specific suffixes only change details such as seals, clearance or cage.
Where are the load ratings for 6311?
Dynamic and static load ratings differ by manufacturer and batch, so they are not published on this page. Load ratings available on request for the specific batch and manufacturer.