Tolerances for Shafts
Important Condition: Shaft and ball bearing made of the same material; otherwise the different expansion coefficients1 must be taken into account.
Shaft Tolerance Selection Guide
| Shaft Motion | Load/Speed Condition | Fit Type | Bearing Tolerance d (0/-5 μm Sorting) | Assembly Accuracy | Typical Applications | Inner Ring State | |
|---|---|---|---|---|---|---|---|
| 0/-2.5 | -2.5/-5 | ||||||
| Rotating or fixed (alternating) | Low loads, low to medium speeds, no vibrations | Sliding fit | -5 / -8 | -8 / -11 | Normal accuracy without special requirements | Guides, Brakes, Clutches | Fixed |
| Fixed | Medium load, medium speed, high frequency vibrations | Interference fit | 0 | -3 | Precise radial guidance, radial rigidity | Gyroscopes | Fixed |
| Rotating | Low loads, medium speed, low frequency vibrations | Interference fit | -3 | -6 | Normal accuracy | Small motors, potentiometers, servomotors | Free |
| Rotating | Medium to high loads | — | +1 | -2 | — | — | Free |
| Fixed | High loads, high speeds, high frequency vibrations | Interference fit | +4 | +1 | Tight fit must be guaranteed at high speeds, high radial rigidity | Rotors, fans, electric motors | Free |
Tolerances for Housing Fits
Important Condition: Housing and ball bearing made of the same material; otherwise the different expansion coefficients1 must be taken into account.
Housing Tolerance Selection Guide
| Outer Ring State | Load/Speed Condition | Fit Type | Bearing Tolerance D (0/-5 μm Sorting) | Assembly Accuracy | Typical Applications | |
|---|---|---|---|---|---|---|
| 0/-2.5 | -2.5/-5 | |||||
| Rotating or fixed (alternating) | Low loads, low to medium speeds, no vibrations | Sliding fit | +5 / +2 | +2 / -1 | Normal accuracy, outer ring must be laterally displaceable (expansion) | Electric motors, servomotors, potentiometers |
| Fixed | Medium load, medium speed, high frequency vibrations | Interference fit | 0 | -3 | Precise radial guidance, radial rigidity, outer ring must be laterally fixed | Synchronous motors, gyro suspensions |
| Rotating | Low loads, low to medium speed, low frequency vibrations | Interference fit | -3 | -6 | Normal accuracy | Guides, tension rollers, pantographs |
| Fixed | High loads, high speeds, high frequency vibrations | Tight fit | -3 | -6 | Tight fit must be guaranteed at high speeds, high rigidity | Rollers, deflection rollers, planetary gears |
| Rotating | Medium to high loads | — | -6 | -9 | — | Rollers |
Technical Notes
1 Coefficient of thermal expansion of ball bearing steel: 11×10-6 /°C
For more detailed information on fit tolerances or technical support, please contact our application engineers.