Komatsu Utility F50003, Operation & Maintenance Manual

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DRIVING TORQUES
175
4.4 DRIVING TORQUES
4.4.1 STANDARD DRIVING 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 screws and nuts with the torque
indicated in the table.
If it is necessary to replace a screw or a nut, always use Komatsu
original spare parts of the same size as those to be replaced.
a
Nm (Newton metre): 1 Nm = 0.102 Kgm
IMPORTANT
q
This driving 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 driving
torques.
RYA02980
Thread
diameter (a)
(mm)
Pitch
(mm) Wrench size
(b) (mm)
8.8 10.9
kgm Nm kgm Nm
6
8
10
12
14
1
1.25
1.5
1.75
2
10
13
17
19
22 0.96 ± 0.1
2.3 ± 0.2
4.6 ± 0.5
7.8 ± 0.8
12.5 ± 1
9.5 ± 1
23 ± 2
45 ± 4.9
77 ± 8
122 ± 13
1.3 ± 0.15
3.2 ± 0.3
6.5 ± 0.6
11 ± 1
17.5 ± 2
13.5 ± 1.5
32.2 ± 3.5
63 ± 6.5
108 ± 11
172 ± 18
16
18
20
22
24 2
2.5
2.5
2.5
3
24
27
30
32
36 19.5 ± 2
27 ± 3
38 ± 4
52 ± 6
66 ± 7
191 ± 21
262 ± 28
372 ± 40
511 ± 57
644 ± 70
27 ± 3
37 ± 4
53 ± 6
73 ± 8
92 ± 10
268 ± 29
366 ± 36
524 ± 57
719 ± 80
905 ± 98
27
30
33
36
39 3
3.5
3.5
4
4
41
46
50
55
60 96 ± 10
131 ± 14
177 ± 20
230 ± 25
295 ± 33
945 ± 100
1287 ± 140
1740 ± 200
2250 ± 250
2900 ± 330
135 ± 15
184 ± 20
250 ± 27
320 ± 35
410 ± 45 1329 ± 140
1810 ± 190
2455 ± 270
3150 ± 350
4050 ± 450