Komatsu D51EX-24, Operation & Maintenance Manual

Page: 286 / 382

STANDARD TIGHTENING TORQUE FOR BOLTS AND
NUTS
Tightening torque list
k k
CAUTION
If nuts, bolts, or other parts are not tightened to the specified torque, it will cause looseness or damage
to the tightened parts, and this will cause failure of the machine or problems with operation. Always be
careful when tightening parts.
Unless otherwise specified, tighten the metric nuts and bolts to
the torque shown in the table below.
If it is necessary to replace any nut or bolt, Komatsu recom-
mends using Komatsu genuine part of the same size as the
part that is removed.
Thread
diameter
of bolt
(a) (mm)
Width
across
flats (b)
(mm)
Tightening torque
Target value Allowable range
Nm kgm Nm kgm
6
8
10
12
14
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 24
27
30
32
36 260
360
510
688
883 26.5
37.0
52.3
70.3
90.0 235 - 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 41
46
50
55
60 1,295
1,720
2,210
2,750
3,280 132.5
175.0
225.0
280.0
335.0 1,150 - 1,440
1,520 - 1,910
1,960 - 2,450
2,450 - 3,040
2,890 - 3,630 118.0 - 147.0
155.0 - 195.0
200.0 - 250.0
250.0 - 310.0
295.0 - 370.0
Apply the following table for hydraulic hose.
STANDARD TIGHTENING TORQUE FOR BOLTS AND NUTS MAINTENANCE
4-10