6306 bearing
30 × 72 mm · dynamic rating 29.6 kN · static rating 16 kN. Dimensions, load ratings, designation meaning, life estimates and equivalent parts.
6306 specification
| Designation | 6306 |
| Type | Deep groove ball bearing |
| Series | 63 medium |
| Bore diameter d | 30 mm |
| Outside diameter D | 72 mm |
| Basic dynamic load rating C | 29.6 kN (29,600 N) |
| Basic static load rating C0 | 16 kN (16,000 N) |
| Ratio C0/C | 0.54 |
| Speed guide, grease lubrication | 13,000 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 6306 means
| Code | Meaning |
|---|---|
| 63 | Deep groove ball bearing, medium dimension series |
| 06 | bore code "06" = 6 × 5 = 30 mm |
Basic rating life of the 6306
Basic rating life is L10 = (C / P)p million revolutions, where P is the equivalent dynamic load and p = 3 (ball bearing). For a 6306 with C = 29.6 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 5.92 kN on this bearing. Use the Load Calculator to work out P for your actual radial and axial loads.
Equivalents of the 6306 from other brands
Deep groove ball bearings follow the ISO basic designation system, so the base number 6306 means the same bore (30 mm) and outside diameter (72 mm) at the major makers. Only the suffixes differ. For sealed versions, common suffixes are -2RS1 or -2Z at SKF, -2RSR or -2ZR at FAG, DDU or ZZ at NSK, and LLU or ZZ at NTN. Check clearance class, grease and seal type before substituting. For brand-specific part numbers, use the Cross-Reference tool.
Where the 6306 is used
Deep-groove ball bearings are chosen for: Radial load with moderate axial load; high-speed compact equipment. Typical equipment: Motors, fans, pumps, gearboxes, auxiliaries. Single/multi-row; insulated or stainless variants available.
Other sizes in the same series
The 6306 belongs to the “63 medium” series. The next size down, the 6305, has a bore of 25 mm and a dynamic rating of 23.4 kN. The next size up, the 6307, has a bore of 35 mm and a rating of 35.1 kN (+19%).
Common problems on bearings like the 6306
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 6306
What are the dimensions of a 6306 bearing?
The 6306 has a bore of 30 mm and an outside diameter of 72 mm. It is a deep groove ball bearing. Series: 63 medium.
What is the load rating of a 6306 bearing?
In the Rotec AI catalogue the 6306 has a basic dynamic load rating C of 29.6 kN and a basic static load rating C0 of 16 kN. Always confirm against the manufacturer's current catalogue.
What is the equivalent of a 6306 bearing?
Use the Cross-Reference tool in Rotec AI to check brand equivalents for the 6306.