MAINTENANCE
STANDARD TIGHTENING TORQUES FOR BOLTS AND NUTS
4-15
STANDARD TIGHTENING TORQUES FOR BOLTS AND
NUTS
4
TORQUE LIST
4
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 pay careful attention 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, always use a Komatsu genuine part of the same size as the part that
was replaced.
Apply the following table for Hydraulic Hose.
Thread
diame-
ter of bolt
(a)(mm)
Width
across
flats
(b)(mm)
Tightening torque
Target value
Service limit
N·m
kgf·m
N·m
kgf·m
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
11.8-14.7
27-34
59-74
98-123
157-196
1.2-1.5
2.8-3.5
6.0-7.5
10.0-12.5
16.0-20.0
16
18
20
22
24
24
27
30
32
36
279
382
549
745
927
28.5
39
56
76
94.5
245-309
343-425
490-608
662-829
824-1030
25.0-31.5
35.0-43.5
50.0-62.0
67.5-84.5
84.0-105.0
27
30
33
36
39
41
46
50
55
60
1320
1720
2210
2750
3280
135.0
175.0
225.0
280.0
335.0
1180-1470
1520-1910
1960-2450
2450-3040
2890-3630
120.0-150.0
155.0-195.0
200.0-250.0
250.0-310.0
295.0-370.0
Thread
diameter
a (mm)
Width
across
flats
b (mm)
Tightening torque
Target value
Permissible range
N·m
kgf·m
N·m
kgf·m
10
14
14.7
1.5
12.7 - 16.7
1.3 - 1.7
14
19
29.4
3.0
27.5 - 39.2
2.8 - 4.0
18
24
78.5
8.0
58.8 - 98.1
6.0 - 10.0
22
27
117.7
12.0
88.3 - 137.3
9.0 - 14.0
24
32
147.1
15.0
117.7 - 176.5
12.0 - 18.0
30
36
215.7
22.0
176.5 - 245.2
18.0 - 25.0
33
41
255.0
26.0
215.7 - 284.4
22.0 - 29.0
Summary of Contents for 76243
Page 2: ......
Page 3: ...FOREWORD 11 ...
Page 5: ...FOREWORD FOREWORD 1 3 q Machine equipped without cab Back pocket of operator s seat ...
Page 16: ...NECESSARY INFORMATION FOREWORD 1 14 ...
Page 17: ...FOREWORD NECESSARY INFORMATION 1 15 ...
Page 24: ...CONTENTS 1 22 ...
Page 28: ...SAFETY LABELS SAFETY 2 4 SAFETY LABELS 2 POSITIONS OF SAFETY PICTOGRAMS 2 ...
Page 289: ...SPECIFICATIONS 15 ...
Page 297: ...INDEX 17 ...
Page 298: ...INDEX 7 2 ...
Page 301: ...COLOPHON 18 ...