Tolerances for shafts and housing fits
Tolerances for shafts
Shaft and ball bearing made of the same material; otherwise the different expansion coefficients 1 must be taken into account.
| Shaft | Load / speeds | Fit | Tolerance d of the ball bearings | Accuracy of the assembly | Typical applications | the inner ring | ||
| 0/–5 μm | Sorting | |||||||
| 0/-2.5 | -2.5/-5 | |||||||
| Tolerance shaft | ||||||||
| Rotating or fixed (alternating) | Low loads, low to medium speeds, no vibrations | Sliding fit | -5 | -5 | -8 | Normal accuracy without special requirements. | Guides | fixed |
| -11 | -8 | -11 | Normal accuracy; the inner ring must be laterally displaceable (expansion). | Brakes Clutches | fixed | |||
| fixed | Medium load, medium speed, high frequency vibrations | Press fit | 0 | 0 | -3 | Precise radial. Radial rigidity | Gyroscopes | fixed |
| rotating | Low loads, medium speed, low frequency vibrations | -6 | -3 | -6 | Normal accuracy | Small motors, potentiometers, servomotors | free | |
| fixed | High loads, high speeds, high frequency vibrations | Press fit | +4 | +4 | +1 | The tight fit must be guaranteed at high speeds. High radial rigidity | Rotors, fans, electric motors | free |
| rotating | Medium to high loads, high speeds, high frequency vibrations | -2 | +1 | -2 | ||||
Tolerances for the housing fits
Housing and ball bearing made of the same material; otherwise the different expansion coefficients 1 must be taken into account
| Outer ring | Load / speeds | Fit | Tolerance d of the ball bearings | Accuracy of the assembly | Typical applications | ||
| 0/–5 μm | Sorting | ||||||
| 0/-2.5 | -2.5/-5 | ||||||
| Tolerance housing | |||||||
| Rotating or fixed (alternating) | Low loads, low to medium speeds, no vibrations | Sliding fit | +5 | +5 | +2 | Normal accuracy without special requirements. Fans, the outer ring must be laterally displaceable (expansion). | Electric motors, servomotors, potentiometers |
| -1 | +2 | -1 | |||||
| fixed | Medium load, medium speed, high frequency vibrations | Press fit | 0 | 0 | -3 | Precise radial guidance, radial rigidity. The outer ring must be laterally fixed. | Synchronous motors, gyro suspensions |
| rotating | Low loads, low to medium speed, low frequency vibrations | -6 | -3 | -6 | Normal accuracy | Guides, tension rollers, pantographs | |
| fixed | High loads, high speeds, high frequency vibrations | Tight fit | -3 | -3 | -6 | A tight fit must be guaranteed at high speeds. | Rollers, deflection rollers, planetary gears |
| rotating | Medium to high loads, high speeds, high frequency vibrations | -9 | -6 | -9 | It is not necessary for the outer ring to be held laterally. High rigidity | ||
1 Coefficient of thermal expansion of ball bearing steel: 11×10-6 ºC