Komatsu PC18MR-3, Operation & Maintenance Manual

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TIGHTENING TORQUES
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4.5 TIGHTENING TORQUES
4.5.1 STANDARD TIGHTENING TORQUES FOR SCREWS AND NUTS
CAUTION
q
If screws, nuts or other parts are not tightened with the required torque, they may become loose or dam-
age the components with which they cooperate, and this may cause machine failures or operation prob-
lems. 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 re-
placed.
a
Nm (Newton metre): 1 Nm = 0.102 kgm
IMPORTANT
q
This tightening torque table is not valid for screws or nuts that must fasten parts made of nylon or simi-
lar materials onto washers or components made of nylon or nonferrous metals or requiring specific
tightening torques.
RYA02980
Thread diame-
ter (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