Mounted Ball Bearings: Fixing Bolts
1. Preparation of the mounting surface
The mounting surface may have a maximum roughness of Ra 12.5 (Rz 63). The surface must be flat within 0.04 mm per 100 mm (IT7). Concave or spherical deviations are not permitted.
2. Select screws
Use suitable fastening screws of strength class 8.8 or higher. Coefficient of friction for the connection: µ = 0.14. Screws are not included in the delivery.
3. Install washers
Place at least one plain washer according to DIN EN ISO 7089/7090 under each screw. Optionally, a spring washer DIN 128 or a conical spring washer DIN 6796 may be used for additional security.
4. Insert screws and tighten by hand
Insert the screws through the housing into the mounting surface. Tighten them by hand until the bearing is seated correctly.
5. Tighten screws with the correct torque
Use a calibrated torque wrench and tighten the screws evenly to the values specified in the table below.
| Tightening torques of fixing bolts for cast iron housings: | |
| Bolt Size | Tightening torques (Nm) |
| M6 | 2,6 – 4,7 |
| M8 | 6 – 10 |
| M10 | 12 – 21 |
| M12 | 21 – 37 |
| M14 | 34 – 60 |
| M16 | 53 – 93 |
| M18 | 77 – 137 |
| M20 | 104 – 186 |
| M22 | 143 – 256 |
| M24 | 204 – 340 |
| M27 | 266 – 478 |
| M30 | 360 – 645 |
| M33 | 494 – 886 |
| M36 | 631 – 1130 |
| M39 | 893 – 1490 |
| M42 | 1110 – 1850 |
| M45 | 1380 – 2300 |