Tightening Fasteners - Yanmar 4JH45 Operation Manual

PERIODIC MAINTENANCE

Tightening Fasteners

Use the correct amount of torque when you tighten fasteners on the engine. 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 Standard Torque 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.
Bolt Diameter x
Pitch (mm)
Tightening N·m
Torque
ft-lb
Taper Plugs
Tightening N·m
Torque
ft-lb
When lock adhesive is applied, decide separately.
Pipe Joint Bolts
Tightening N·m
Torque
ft-lb
When seal washer applied, torque is 34 ± 5 N·m (25.1 ± 3.7 ft-lb).
76
M6x1.0 M8x1.25
10.8 ± 1.0 25.5 ± 3.0
8.0 ± 0.7 18.8 ± 2.2
1/8
9.8
7.4
M8 M10
14.7 ± 2 22.5 ± 3
10.9 ± 1.5 16.6 ± 2.2
M10x1.5 M12x1.75
49 ± 5.0 88.2 ± 10.0
36.2 ± 3.7 65.1 ± 7.4
1/4 3/8
19.6 29.4
14.5 21.7
M12
29.4 ± 5
21.7 ± 3.7
JH Series Operation Manual
M14x1.5 M16x1.5
140.0 ± 10.0 230.0 ± 10.0
103 ± 7.2 170 ± 7.2
1/2
58.8
43.2
M14 M16
44.1 ± 5 53.9 ± 5
32.6 ± 3.7 69.8 ± 3.7