Standard Tightening Torques For Bolts And Nuts; Torque List - Komatsu D61EX-12 Operation And 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.
Thead Width
diameter across
flat
Target value
a(mm) b(mm)
6 10
8 13
10 17
12 19
14 22
16 24
18 27
20 30
22 32
24 36
27 41
30 46
33 50
36 55
39 60
Apply the following table for Hydraulic Hose.
Thread Width
diameter across
flat
a(mm) b(mm)
14 19
18 24
22 27
24 32
30 36
33 41
4-14
Tightening torque [N•m (kgf•m)]
Service limit
13.2 (1.35) 11.8 - 14.7 (1.2 - 1.5)
31 (3.2) 27
66 (6.7) 59
113 (11.5) 98
177 (18.0) 157
279 (28.5) 245 - 309 (25.0 - 31.5)
382 (39.0) 343 - 425 (35.0 - 43.5)
549 (56.0) 490 - 608 (50.0 - 62.0)
745 (76.0) 662 - 829 (67.5 - 84.5)
927 (94.5) 824 - 1030 (84.0 - 105.0)
1320 (135.0) 1180 - 1470 (120.0 - 150.0)
1720 (175.0) 1520 - 1910 (155.0 - 195.0)
2210 (225.0) 1960 - 2450 (200.0 - 250.0)
2750 (280.0) 2450 - 3040 (250.0 - 310.0)
3280 (335.0) 2890 - 3630 (295.0 - 370.0)
Tightening torque [N•m (kgf•m)]
Target value Service limit
44.1 (4.5) 34.3 - 63.7 (6.0 - 10.0)
78.5 (8.0) 58.8 - 98.1 (6.0 - 10.0)
117.7 (12.0) 88.3 - 137.3 (9.0 - 14.0)
147.1 (15.0) 117.7 - 176.5 (12.0 - 18.0)
215.7 (22.0) 176.5 - 245.2 (18.0 - 25.0)
255.0 (26.0) 215.7 - 284.4 (22.0 - 29.0)
CAUTION
- 34 (2.8 - 3.5)
- 74 (6.0 - 7.5)
- 123 (10.0 - 12.5)
- 196 (16.0 - 20.0)
MAINTENANCE