11
Maintenance
11.4
Tightening torques
96
Bellima F 130
Original Operating Instructions 150000148_06_en
Metric thread screws with countersunk head and hexagon socket
INFORMATION
The table applies only to countersunk screws with hexagon socket and metric thread
tightened via hexagon socket.
DV000-000
X
Thread size
1
Strength class on screw head
X
Strength class
5.6
8.8
10.9
12.9
Tightening torque (Nm)
M4
2.5
3.5
4.1
M5
4.7
7
8
M6
8
12
15
M8
20
29
35
M10
23
39
58
67
M12
34
68
100
116
M14
108
160
188
M16
168
248
292
M20
340
488
568
Locking screws on the gearboxes
INFORMATION
The tightening torques only apply to assembly of locking screws, viewing glasses, ventilation
and breather filters and bleed valves in gearboxes with cast housings or aluminium or steel
housings. The term “locking screw” includes the drain plug, the inspection screw as well as
the ventilation and breather filters.
The table only applies to locking screws with external hexagon together with copper seal ring
and for bleed valves made of brass with shaped seal ring.
