7311 BEP bearing
55 × 120 mm · dynamic rating 79.3 kN · static rating 55 kN. Dimensions, load ratings, designation meaning, life estimates and equivalent parts.
7311 BEP specification
| Designation | 7311 BEP |
| Type | Single-row angular contact ball bearing |
| Series | 73 medium |
| Bore diameter d | 55 mm |
| Outside diameter D | 120 mm |
| Basic dynamic load rating C | 79.3 kN (79,300 N) |
| Basic static load rating C0 | 55 kN (55,000 N) |
| Ratio C0/C | 0.69 |
| Speed guide, grease lubrication | 6,700 rpm |
| Life exponent p | 3 (ball bearing) |
Values come from the Rotec AI bearing catalogue and are indicative. Confirm against the manufacturer's current catalogue before ordering. Not every dimension (such as width) is listed here.
What the designation 7311 BEP means
| Code | Meaning |
|---|---|
| 73 | Angular contact ball bearing, medium dimension series |
| 11 | bore code "11" = 11 × 5 = 55 mm |
| B | 40° contact angle |
| E | Optimized internal design |
| P | Glass-fibre-reinforced PA66 cage, ball-centred |
Basic rating life of the 7311 BEP
Basic rating life is L10 = (C / P)p million revolutions, where P is the equivalent dynamic load and p = 3 (ball bearing). For a 7311 BEP with C = 79.3 kN, the table shows what that gives at different load levels. It is the ISO 281 basic life only: it does not include lubrication, contamination, misalignment or reliability modifiers.
| C / P | P as share of C | L10 (million rev) | L10 at 1,500 rpm | L10 at 3,000 rpm |
|---|---|---|---|---|
| 3 | 33.3% | 27 | 300 | 150 |
| 5 | 20.0% | 125 | 1,400 | 690 |
| 8 | 12.5% | 512 | 5,700 | 2,800 |
| 12 | 8.3% | 1,728 | 19,200 | 9,600 |
For example, a C / P of 5 means the equivalent load is 15.86 kN on this bearing. Use the Load Calculator to work out P for your actual radial and axial loads.
Equivalents of the 7311 BEP
Brand-by-brand equivalents for this exact designation are not shown here. The Cross-Reference tool accepts SKF, FAG, NSK, NTN, Timken, Koyo and NRB designations, and shows what is catalogued.
Where the 7311 BEP is used
Angular-contact ball bearings are chosen for: Combined radial and axial load; precision/high-speed arrangements. Typical equipment: Pumps, compressors, spindles, generators, aerospace accessories. Often paired/preloaded; contact angle and lubrication matter.
Other sizes in the same series
The 7311 BEP belongs to the “73 medium” series. The next size down, the 7310 BECBP, has a bore of 50 mm and a dynamic rating of 75 kN. The next size up, the 7312 BEP, has a bore of 60 mm and a rating of 95.6 kN (+21%).
Common problems on bearings like the 7311 BEP
Most field failures trace back to lubrication, contamination, fits and alignment rather than the bearing itself. These guides explain how to recognise and prevent them:
Questions about the 7311 BEP
What are the dimensions of a 7311 BEP bearing?
The 7311 BEP has a bore of 55 mm and an outside diameter of 120 mm. It is a single-row angular contact ball bearing. Series: 73 medium.
What is the load rating of a 7311 BEP bearing?
In the Rotec AI catalogue the 7311 BEP has a basic dynamic load rating C of 79.3 kN and a basic static load rating C0 of 55 kN. Always confirm against the manufacturer's current catalogue.
What is the equivalent of a 7311 BEP bearing?
Use the Cross-Reference tool in Rotec AI to check brand equivalents for the 7311 BEP.