30208 bearing
40 × 80 mm · dynamic rating 75.8 kN · static rating 68 kN. Dimensions, load ratings, designation meaning, life estimates and equivalent parts.
30208 specification
| Designation | 30208 |
| Type | Tapered roller bearing |
| Series | 302 standard-angle |
| Bore diameter d | 40 mm |
| Outside diameter D | 80 mm |
| Basic dynamic load rating C | 75.8 kN (75,800 N) |
| Basic static load rating C0 | 68 kN (68,000 N) |
| Ratio C0/C | 0.90 |
| Speed guide, grease lubrication | 8,500 rpm |
| Life exponent p | 10/3 (roller 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 30208 means
| Code | Meaning |
|---|---|
| 302 | Tapered roller bearing, standard contact angle series |
| 08 | bore code "08" = 8 × 5 = 40 mm |
Basic rating life of the 30208
Basic rating life is L10 = (C / P)p million revolutions, where P is the equivalent dynamic load and p = 10/3 (roller bearing). For a 30208 with C = 75.8 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% | 39 | 430 | 220 |
| 5 | 20.0% | 214 | 2,400 | 1,200 |
| 8 | 12.5% | 1,024 | 11,400 | 5,700 |
| 12 | 8.3% | 3,956 | 44,000 | 22,000 |
For example, a C / P of 5 means the equivalent load is 15.16 kN on this bearing. Use the Load Calculator to work out P for your actual radial and axial loads.
Equivalents of the 30208
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 30208 is used
Tapered roller bearings are chosen for: Combined radial and axial load; stiffness. Typical equipment: Wheel hubs, gearboxes, rail wheelsets, construction/agri equipment. Usually adjusted/preloaded; paired arrangements common.
Other sizes in the same series
The 30208 belongs to the “302 standard-angle” series. The next size down, the 30207, has a bore of 35 mm and a dynamic rating of 63.2 kN. The next size up, the 30209, has a bore of 45 mm and a rating of 81.6 kN (+8%).
Common problems on bearings like the 30208
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 30208
What are the dimensions of a 30208 bearing?
The 30208 has a bore of 40 mm and an outside diameter of 80 mm. It is a tapered roller bearing. Series: 302 standard-angle.
What is the load rating of a 30208 bearing?
In the Rotec AI catalogue the 30208 has a basic dynamic load rating C of 75.8 kN and a basic static load rating C0 of 68 kN. Always confirm against the manufacturer's current catalogue.
What is the equivalent of a 30208 bearing?
Use the Cross-Reference tool in Rotec AI to check brand equivalents for the 30208.