Standard Tightening Torques For Bolts And Nuts; Torque List - Komatsu D65EX-12 Operation & Maintenance Manual

STANDARD TIGHTENING TORQUES FOR BOLTS AND NUTS

STANDARD TIGHTENING TORQUES FOR BOLTS
AND NUTS

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 pay careful attention when tightening parts.
Unless otherwise specified, tighten the metric nuts and bolts to the torque shown in the table below.
The tightening torque is determined by the width across the flats of the nut and bolt.
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.
Width
Thread across
Target value
diameter flat b
a (mm) (mm) N•m kgf•m
6 10 13.2
8 13 31
10 17 66
12 19 113
14 22 177
16 24 279
18 27 382
20 30 549
22 32 745
24 36 927
27 41 1320 135.0
30 46 1720 175.0
33 50 2210 225.0
36 55 2750 280.0
39 60 3280 335.0
Apply the following table for Hydraulic Hose.
Width
Thread across
Target value
diameter flat b
a (mm) (mm) N•m
14 19 29.4
18 24 78.5
22 27 117.7
24 32 147.1
30 36 215.7
33 41 255.0
4-16
Tightening torque
lbft N•m
1.35 9.8 11.8 - 14.7
3.2 23.1 27 - 34
6.7 48.5 59 - 74
11.5 83.2 98 - 123
18 130.2 157 - 196
28.5 206.1 245 - 309
39 282.1 343 - 425
56 405.0 490 - 608
76 549.7 662 - 829
94.5 683.5 824 - 1030
976.5 1180 - 1470
1265.8 1520 - 1910
1627.4 1960 - 2450
2025.2 2450 - 3040
2423.1 2890 - 3630
Tightening torque
kgf•m lbft N•m
3.0 21.7 27.5 - 39.2
8.0 57.3 58.8 - 98.1
12.0 86.8 88.3 - 137.3
15.0 108.5 117.7 - 176.5 12.0 - 18.0
22.0 159.1 176.5 - 245.2 18.0 - 25.0 130.2 - 180.8
26.0 188.1 215.7 - 284.4 22.0 - 29.0 159.1 - 209.8
CAUTION
Service limit
kgf•m lbft
1.2 - 1.5 8.7 - 10.8
2.8 - 3.5 20.3 - 25.3
6.0 - 7.5 43.4 - 54.2
10.0 - 12.5 72.3 - 90.4
16.0 - 20.0 115.7 - 144.7
25.0 - 31.5 180.8 - 227.8
35.0 - 43.5 253.2 - 314.6
50.0 - 62.0 361.7 - 448.4
67.5 - 84.5 488.2 - 611.2
84.0 - 105.0 607.6 - 759.5
120.0 - 150.0 868.0 - 1085.0
155.0 - 195.0 1121.1 - 1410.4
200.0 - 250.0 1446.6 - 1808.3
250.0 - 310.0 1808.3 - 2242.2
295.0 - 370.0 2133.7 - 2676.2
Service limit
kgf•m lbft
2.8 - 4.0 20.3 - 28.9
6.0 - 10.0 43.4 - 72.3
9.0 - 14.0 65.1 - 101.3
86.8 - 130.2
MAINTENANCE