Komatsu PC118MR-8, Operation And Maintenance Manual

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MAINTENANCE
TIGHTENING TORQUES
4-15
TIGHTENING TORQUES 4
STANDARD TIGHTENING TORQUES FOR SCREWS AND NUTS 4
CAUTION
If screws, nuts or other parts are not tightened with the required torque, they may become loose or
damage the components with which they cooperate, and this may cause machine failures or operation
problems. Always pay the utmost attention when carrying out tightening operations.
If not specified otherwise, tighten the screws and nuts applying
the torques specified in the table.
If it is necessary to replace a screw or a nut, always use
Komatsu original spare parts having the same size of the part
to be replaced.
q
Nm (Newton metre): 1 Nm = 0.102 kgm
NOTICE
This tightening torque table is not valid for screws or nuts that must fasten parts made of nylon or similar
materials onto washers or components made of nylon or nonferrous metals or requiring specific
tightening torques.
Thread
diameter (a)
(mm)
Pitch
(mm)
Wrench size
(b) (mm)
Driving torque:
Standard value Use limit
Nm kgm Nm kgm
6
8
10
12
14
1
1.25
1.5
1.75
2
10
13
17
19
22
13.2
31
66
113
172
1.35
3.2
6.7
11.5
17.5
11.8 – 14.7
27 – 34
59 – 74
98 – 123
153 – 190
1.2 – 1.5
2.8 – 3.5
6.0 – 7.5
10.0 – 12.5
15.5 – 19.5
16
18
20
22
24
2
2.5
2.5
2.5
3
24
27
30
32
36
260
360
510
688
883
26.5
37
52.3
70.3
90
235 – 285
320 – 400
455 – 565
610 – 765
785 – 980
23.5 – 29.5
33.0 – 41.0
46.5 – 58.0
62.5 – 78.0
80.0 – 100.0
27
30
33
36
39
3
3.5
3.5
4
4
41
46
50
55
60
1295
1720
2210
2750
3280
132.5
175.0
225.0
280.0
335.0
1150 – 1440
1520 – 1910
1960 – 2450
2450 – 3040
2890 – 3630
118.0 – 147.0
155.0 – 195.0
200.0 – 250.0
250.0 – 310.0
295.0 – 370.0
WEAM014802