Komatsu PC1250-11, Original Instructions Manual

Page: 324 / 452

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
diame-
ter of
bolt “a”
(mm)
Width
across
flats “b”
(mm)
Tightening torque
Target value Allowable range
Nm kgm lbft Nm kgm lbft
6
8
10
12
14
10
13
17
19
22 13.2
31
66
113
177
1.35
3.2
6.7
11.5
18
9.8
22.8
48.5
83.2
130
11.8 to 14.7
27 to 34
59 to 74
98 to 123
157 to 196
1.2 to 1.5
2.8 to 3.5
6 to 7.5
10 to 12.5
16 to 20
8.7 to 10.8
20.3 to 25.3
43.4 to 54.2
72.3 to 90.4
116 to 145
16
18
20
22
24 24
27
30
32
36 279
382
549
745
927 28.5
39
56
76
94.5
206
282
405
550
684 245 to 309
343 to 425
490 to 608
662 to 829
824 to 1030
25 to 31.5
35 to 43.5
50 to 62
67.5 to 84.5
84 to 105
181 to 228
253 to 315
362 to 448
488 to 611
608 to 759
27
30
33
36
39 41
46
50
55
60 1320
1720
2210
2745
3280 135
175
225
280
335 976
1270
1630
2030
2420
1180 to 1470
1520 to 1910
1960 to 2450
2450 to 3040
2890 to 3630
120 to 150
155 to 195
200 to 250
250 to 310
295 to 370 868 to 1080
1120 to 1410
1450 to 1810
1810 to 2240
2130 to 2680
42 65 3830 390 2820 3430 to 4220 335 to 430 2420 to 3110
STANDARD TIGHTENING TORQUE FOR BOLTS AND NUTS MAINTENANCE
4-8