Mooney M20K - Page 19

8ERVICE
AND
MAINTENANCE
MANUAL
M20K
MOONEY
AIRCRAFT
CORPORATION
BOLT
NUT
TORQUE
VALUES
METRO
BOLTS,
SCRR~IS
8
NUTS
Failure
of
threaded
fasteners
due
to
over-tightening
can
occur
by
bolt
shank
fracture
or
by
stripping
of the
nut
and/or
bolts
thread.
A
bolt
or screw
assembled
with
a
nut
of the
appropn’ate
class is
intended
to
provide
an
assembly
capable
of
being
tightened
to
the
bolt
proof
load
without
thread
stn’pping
occurring.
The
torque
value
to
be
set
for
a
particular
size
of
screw
is
dependent upon:
1)
Maten’al
of the
screw.
2)
Parent
material
(steel,
non-ferrous
metal
or
plastic).
3)
\I~hether
the
screw
is
untreated
or
plated.
4)
V~hether
the
screw
is
dry
or
lubricated.
5)
The
depth
of the
thread.
TIGHTENING
TORQUES
Untreated
Screw(Black
Finish)
Fiiction
Coeficient
0.14
NOMINAL
PROPERTY
DIAMETER
CLASS
(Coarse
Thread)
TORQUE
Ma
5.6
8.8
10.9
12.9
Nm/ft.lb.
Nm/ft.lb.
Nmift.lb.
Nm/ft.lb.
M3
0.60/0.44
1.37/1.01
1.92/1.42
230/1 .70
M4
1.37/1.01
3.10/2~29
4.40/3~25
5.25/3.87
M5
2.70/1.99
6.15/4.54
8.65/6.38
10.4/7.6
M6
4.6/3.3
10.5/7.7
15/11
18/13
M7
7.6/5.6
17.5M
2.9
25/1 8.4
29121
.3
M8
11/8.1
26/19
36/26
43/31
Mig
22/16
51/37
72/53
87164
M?2
39/28
89/65
125/92
150/110
M14
62/45
141/103
198/146
240/177
M?6
95/70
215/158
305~224
365/269
M18
130/95
295/217
420/309
500/368
M20
184/135
420/309
590/435
71
0/523
M22
250/1 84
570/420
800/590
960/708
M24
31
5/232
725/534
1020/752
1220/899
Mn
470/346
1070/789
1510/1113
1810/1334
M30
635/468
1450/1
069
2050/1
511
2450/1 806
M33
865/637
i
970/1 452
2770/2042
3330/2455
M36
1111/819
2530/1
855
3560/2625
4280/3156
M39
1440/1062
3290/2426
4620/3407
5550/4093
5-20-01
OLDWILLWAYNE