7309 BEP /DB bearing
45 × 100 mm · dynamic rating 90.56 kN · static rating 75 kN. Dimensions, load ratings, designation meaning, life estimates and equivalent parts.
7309 BEP /DB specification
| Designation | 7309 BEP /DB |
| Type | Matched pair of angular contact ball bearings (back-to-back) |
| Series | 73 medium (pair) |
| Bore diameter d | 45 mm |
| Outside diameter D | 100 mm |
| Basic dynamic load rating C | 90.56 kN (90,558 N) |
| Basic static load rating C0 | 75 kN (75,000 N) |
| Ratio C0/C | 0.83 |
| Speed guide, grease lubrication | 7,200 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 7309 BEP /DB means
| Code | Meaning |
|---|---|
| 73 | Angular contact ball bearing, medium dimension series |
| 09 | bore code "09" = 9 × 5 = 45 mm |
| B | 40° contact angle |
| E | Optimized internal design |
| P | Glass-fibre-reinforced PA66 cage, ball-centred |
| /DB | Two bearings mounted back-to-back as a matched pair — carries combined radial + axial load from both directions with high stiffness |
Basic rating life of the 7309 BEP /DB
Basic rating life is L10 = (C / P)p million revolutions, where P is the equivalent dynamic load and p = 3 (ball bearing). For a 7309 BEP /DB with C = 90.56 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 18.11 kN on this bearing. Use the Load Calculator to work out P for your actual radial and axial loads.
Equivalents of the 7309 BEP /DB
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 7309 BEP /DB 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 7309 BEP /DB belongs to the “73 medium (pair)” series. The next size down, the 7308 BEP /DB, has a bore of 40 mm and a dynamic rating of 74.84 kN. The next size up, the 7310 BECBP /DB, has a bore of 50 mm and a rating of 121.5 kN (+34%).
Common problems on bearings like the 7309 BEP /DB
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 7309 BEP /DB
What are the dimensions of a 7309 BEP /DB bearing?
The 7309 BEP /DB has a bore of 45 mm and an outside diameter of 100 mm. It is a matched pair of angular contact ball bearings (back-to-back). Series: 73 medium (pair).
What is the load rating of a 7309 BEP /DB bearing?
In the Rotec AI catalogue the 7309 BEP /DB has a basic dynamic load rating C of 90.56 kN and a basic static load rating C0 of 75 kN. Always confirm against the manufacturer's current catalogue.
What is the equivalent of a 7309 BEP /DB bearing?
Use the Cross-Reference tool in Rotec AI to check brand equivalents for the 7309 BEP /DB.