Standard Tightening Torque For Bolts And Nuts - Komatsu D65EX-18 Operation & Maintenance Manual

STANDARD TIGHTENING TORQUE FOR BOLTS AND NUTS

STANDARD TIGHTENING TORQUE FOR BOLTS AND
NUTS
Tightening torque list
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
Width
diame-
across
ter of
flats (b)
bolt (a)
(mm)
Nm
(mm)
6 10 13.2
8 13
10 17
12 19 113
14 22 172
16 24 260
18 27 360
20 30 510
22 32 688
24 36 883
27 41 1,295
30 46 1,720
33 50 2,210
36 55 2,750
39 60 3,280
4-12
k k
Target value
kgm lbft
1.35 9.8
31 3.2 23.1
66 6.7 48.5
11.5 83.2
17.5 130.2
26.5 206.1
37.0 282.1
52.3 405.0
70.3 549.7
90.0 683.5
132.5 976.5
175.0 1,265.8
225.0 1,627.4
280.0 2,025.2
335.0 2,423.1
CAUTION
Tightening torque
Nm
11.8 - 14.7
27 - 34
59 - 74
98 - 123
153 - 190
235 - 285
320 - 400
455 - 565
610 - 765
785 - 980
1,150 - 1,440
1,520 - 1,910
1,960 - 2,450
2,450 - 3,040
2,890 - 3,630
MAINTENANCE
Allowable range
kgm
1.2 - 1.5
2.8 - 3.5 20.3 - 25.3
6.0 - 7.5 43.4 - 54.2
10.0 - 12.5 72.3 - 90.4
15.5 - 19.5 115.7 - 144.7
23.5 - 29.5 180.8 - 227.8
33.0 - 41.0 253.2 - 314.6
46.5 - 58.0 361.7 - 448.4
62.5 - 78.0 488.2 - 611.2
80.0 - 100.0 607.6 - 759.5
118.0 - 147.0 868.0 - 1,085.0
155.0 - 195.0 1,121.1 - 1,410.4
200.0 - 250.0 1,446.6 - 1,808.3
250.0 - 310.0 1,808.3 - 2,242.2
295.0 - 370.0 2,133.7 - 2,676.2
lbft
8.7 - 10.8