4-6
4. Assembly
4.
Assembly
LM Guide
4-2
When Measuring the Running Accuracy for Single Rail
Application
When measuring running accuracy of the LM block, stable accuracy can be obtained by securing
two LM blocks on an inspection plate, as shown in Figure 4-17. When using a dial gauge, we
recommend placing a straight-edge as close as possible to the LM block in order to perform
accurate measurement.
2) Measurement method using a dial gauge
1) Measurement method using an autocollimator
Figure 4-17 Methods for Measuring Accuracy after Installation
4-3
Recommended Tightening Torque for LM Rails
On the high-precision LM rails of the LM Guide, the rails are tightened with bolts for the final
grinding of the raceways and for the accuracy inspection. When mounting a high-precision LM
rail onto a machine, we recommend using the corresponding tightening torque indicated in
Table 4-1 or Table 4-2.
Table 4-1 When Using Pan Head Screws
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 4-2 When Using Hexagonal-Socket-
Head Type Bolts
Unit: N-cm
Screw model No.
Tightening torque
Iron
Casting 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
1370
921
686
M 8
3040
2010
1470
M 10
6760
4510
3330
M 12
11,800
7840
5880
M 14
15,700 10,500
7840
M 16
19,600 13,100
9800
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
