Tightening Torque Specifications; Tightening Torque List - Komatsu PC1250-7 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
of bolt flats
Target value
(a)(mm) (b)(mm)
6 10 13.2 (1.35)
8 13
10 17
12 19 113 (11.5)
14 22 177 (18.0)
16 24 279 (28.5)
18 27 382 (39.0)
20 30 549 (56.0)
22 32 745 (76.0)
24 36 927 (94.5)
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)
42 65 3830 (390.0) 3430 - 4220 (350.0 - 430.0)
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 - 14
Tightninig torque [Nm (kgm)]
Permissible range
11.8 - 14.7 (1.2 - 1.5)
31 (3.2) 27 - 34 (2.8 - 3.5)
66 (6.7) 59 - 74 (6.0 - 7.5)
98 - 123 (10.0 - 12.5)
157 - 196 (16.0 - 20.0)
245 - 309 (25.0 - 31.5)
343 - 425 (35.0 - 43.5)
490 - 608 (50.0 - 62.0)
662 - 829 (67.5 - 84.5)
824 - 1030 (84.0 - 105.0)
1180 - 1470 (120.0 - 150.0)
1520 - 1910 (155.0 - 195.0)
1960 - 2450 (200.0 - 250.0)
2450 - 3040 (250.0 - 310.0)
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
MAINTENANCE