Yanmar YDG Series, Operation Manual

Page: 60 / 92

PERIODIC MAINTENANCE
46
YDG Operation Manual
TIGHTENING TORQUES FOR STANDARD BOLTS AND NUTS
Use the correct amount of torque when you tighten fasteners on the machine. Applying excessive torque
may damage the fastener or component and not enough torque may cause a leak or component failure.
NOTICE
The tightening torque in the following chart should be applied only to the bolts with a “7” head. (JIS strength
classification: 7T) Apply 60 % torque to bolts that are not listed. Apply 80 % torque when tightened to
aluminum alloy.
Note: Torque values shown in this manual are for clean, non-lubricated fasteners unless otherwise
specified.
Item
Nominal thread
diameter

pitch
Tightening torque Remarks
Hexagon bolt
(7T) and nut
M6

1.0 mm
7 - 9 lb-ft
(87 - 104 lb-in., 9.8 -11.8 N·m, 1.0 - 1.2 kgf·m)
Use 80 % of the value at left
when the tightening part is
aluminum.
Use 60 % of the value at left
for 4T bolts and locknuts.
M8

1.25 mm
17 - 21 lb-ft
(200 - 251 lb-in., 22.6 - 28.4 N·m, 2.3 - 2.9 kgf·m)
M10

1.5 mm
33 - 40 lb-ft
(44.1 - 53.9 N·m, 4.5 - 5.5 kgf·m)
M12

1.75 mm
58 - 72 lb-ft
(78.4 - 98.0 N·m, 8.0 - 10 kgf·m)
M14

1.5 mm
94 - 108 lb-ft
(127.5 - 147.1 N·m, 13 - 15 kgf·m)
M16

1.5 mm
159 - 174 lb-ft
(215.7 - 235.4 N·m, 22 - 24 kgf·m)
PT plug
1/8
7 lb-ft
(87 lb-in., 9.8 N·m, 1.0 kgf·m)
–
1/4
14 lb-ft
(173 lb-in., 19.6 N·m, 2.0 kgf·m)
3/8
22 lb-ft
(29.4 N·m, 3.0 kgf·m)
1/2
43 lb-ft
(58.8 N·m, 6.0 kgf·m)
Pipe joint bolt
M8
9 - 12 lb-ft
(112 - 148 lb-in., 12.7 - 16.7 N·m, 1.3 - 1.7 kgf·m)
–
M10
14 - 19 lb-ft
(173 - 225 lb-in., 19.6 - 25.4 N·m, 2.0 - 2.5 kgf·m)
M12
18 - 25 lb-ft
(24.5 - 34.3 N·m, 2.5 - 3.5 kgf·m)
M14
29 - 36 lb-ft
(39.2 - 49.0 N·m, 4.0 - 5.0 kgf·m)
M16
36 - 43 lb-ft
(49.0 - 58.8 N·m, 5.0 - 6.0 kgf·m)