Tightening the Hexagon Socket Head Cap Bolts
Hexagon socket head cap bolts (referred to as "bolts" below) are used in locations where mechanical strength is required. During assembly, these bolts are tightened at the tightening torques shown in the following table.
Unless otherwise specified, when retightening these bolts in the work procedures described in this manual, use a torque wrench or similar tool to obtain the tightening torques in the following table.
| Bolt | Tightening Torque |
|---|---|
| M3 | 2.0 ± 0.1 N·m (21 ± 1 kgf·cm) |
| M4 | 4.0 ± 0.2 N·m (41 ± 2 kgf·cm) |
| M5 | 8.0 ± 0.4 N·m (82 ± 4 kgf·cm) |
| M6 | 13.0 ± 0.6 N·m (133 ± 6 kgf·cm) |
| M8 | 32.0 ± 1.6 N·m (326 ± 16 kgf·cm) |
| M10 | 58.0 ± 2.9 N·m (590 ± 30 kgf·cm) |
| M12 | 100.0 ± 5.0 N·m (1,020 ± 51 kgf·cm) |
For set screw, refer to the following table.
| Set Screw | Tightening Torque |
|---|---|
| M4 | 2.4 ± 0.1 N·m (26 ± 1 kgf·cm) |
| M5 | 3.9 ± 0.2 N·m (40 ± 2 kgf·cm) |
| M6 | 8.0 ± 0.4 N·m (82 ± 4 kgf·cm) |
It is recommended that bolts arranged in a circular pattern be secured in place by tightening in criss-cross order as shown in the figure.
| Symbol | Description |
|---|---|
| a | Threaded holes |
When securing the bolts, do not tighten the bolts all at once, but tighten them in two or three separate rounds with an Allen wrench, and then use a torque wrench or similar tool to secure them at the tightening torques shown in the table above.