Tightening Torque Specifications; Tightening Torque List - Komatsu PC308USLC-3E0 Operation & Maintenance Manual

TIGHTENING TORQUE SPECIFICATIONS

TIGHTENING TORQUE SPECIFICATIONS

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 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.
Thread Width
diameter across
Target value
of bolt flats
Nm kgm
(a)(mm) (b)(mm)
6 10 13.2 1.35
8 13 31 3.2
10 17 66 6.7
12 19 113 11.5
14 22 172 17.5
16 24 260 26.5
18 27 360
20 30 510 52.3
22 32 688 70.3
24 36 883
27 41 1295 132.5
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
diameter a
flat
(mm)
b(mm)
9/16 -18UNF 19
11/16 -16UN 22
13/16 -16UN 27
1 -14UNS 32
1 · 3/16 -12UN
36
*1-7/16-12UN
41
-2B
The torques marked * indicate the tightening torques for the hoses at the top of the swivel joint.
4 - 12
Tightening torque
Service limit
lbft Nm kgm
9.8 11.8-14.7 1.2-1.5
23.1 27-34 2.8-3.5
48.5 59-74 6.0-7.5
83.2 98-123 10.0-12.5
126.6 153-190 15.5-19.5
191.7 235-285 23.5-29.5
37 267.6 320-400 33.0-41.0
378.3 455-565 46.5-58.0
508.5 610-765 62.5-78.0
90 651 785-980 80.0-100.0
958.4 1150-1440 118.0-147.0
1265.8 1520-1910 155.0-195.0
1627.4 1960-2450 200.0-250.0
2025.2 2450-3040 250.0-310.0
2423.1 2890-3630 295.0-370.0
Tightening torque [Nm (kgm)]
Target
Permissible range
value
44 (4.5) 35 - 54 (3.5 - 5.5)
74 (7.5) 54 - 93 (5.5 - 9.5)
103 (10.5) 84 - 132 (8.5 - 13.5)
157 (16.0) 128 - 186 (13.0 - 19.0)
216 (22.0) 177 - 245 (18.0 - 25.0)
215 (22) 176 - 234 (18 - 24)
CAUTION
lbft
8.7-10.8
20.3-25.3
43.4-54.2
72.3-90.4
112.1-141
170.0-213.4
238.7-296.6
336.3-419.5
452.1-564.2
578.6-723.3
853.5-1063.3
1121.1-1410.4
1446.6-1808.3
1808.3-2242.2
2133.7-2676.2
MAINTENANCE