Recommended Tightening Torque for LM Rails
LM rails for high-precision LM Guide units have their raceways ground and accuracy inspected while the rails are secured with bolts. When mounting a high-precision LM rail on a machine, we recommend using the corresponding tightening torque indicated in Table 1 or Table 2.
Table 1: Tightening Torques when Pan Head Screws are Used
Unit: N･cm
| Screw model No. |
Tightening torque | |
|---|---|---|
| Not hardened | Hardened | |
| M 2 | 17.6 | 21.6 |
| M 2.3 | 29.4 | 35.3 |
| M 2.6 | 44.1 | 52.9 |
Table 2: Tightening Torques when Hexagonal-Socket-Head Type Bolts are Used
Unit: N･cm
| Screw model No. |
Tightening torque | ||
|---|---|---|---|
| Steel | Cast Iron | Aluminum | |
| M 2 | 58.8 | 39.2 | 29.4 |
| M 2.3 | 78.4 | 53.9 | 39.2 |
| M 2.6 | 118 | 78.4 | 58.8 |
| M 3 | 196 | 127 | 98 |
| M 4 | 412 | 274 | 206 |
| M 5 | 882 | 588 | 441 |
| M 6 | 1,370 | 921 | 686 |
| M 8 | 3,040 | 2,010 | 1,470 |
| M 10 | 6,760 | 4,510 | 3,330 |
| M 12 | 11,800 | 7,840 | 5,880 |
| M 14 | 15,700 | 10,500 | 7,840 |
| M 16 | 19,600 | 13,100 | 9,800 |
| M 20 | 38,200 | 25,500 | 19,100 |
| M 22 | 51,900 | 34,800 | 26,000 |
| M 24 | 65,700 | 44,100 | 32,800 |
| M 30 | 130,000 | 87,200 | 65,200 |
