TM 55-1520-240-23-1
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SELF-RETAINING BOLTS INSTALLATION
(Continued)
1-14
c.
Place washer(s) on bolt.
d.
Install nut as follows:
If a thin washer is used under the
nut, do not let the inner diameter of
the washer become caught on the
bolt retaining element. False torque
readings and damage to the hardware
can result.
(1)
Torque nut to the minimum applicable
torque. Check that no axial looseness
exists in bolt-nut stackup. CHECK
THAT MINIMUM TORQUE OF 10
INCH-POUNDS IS REQUIRED TO
ROTATE BOLT-NUT STACKUP. Correct
low rotation torque or axial looseness
by adding a washer under nut, repeat
torquing.
(2)
Install cotter pin if nut castellations are
aligned with pin hole. If castellations
are not in line with pin hole, tighten nut
as required for alignment. Install cotter
pin. Do not exceed maximum allowable
torque.
NOTE
Abrupt increases in torque required
to tighten nut is an indication of
bottomed thread or jammed washer.
Remove nut and examine hardware if
such damage is suspected.
Torque in Inch-Pounds for Nuts Used With Impedance Bolts
NUT
MINIMUM TORQUE
MAXIMUM
TORQUE
MS21224-3
15
20
MS21224-4
30
45
MS21224-5
60
90
MS21224-6
85
125
MS21224-7
155
220
MS21224-8
195
280
MS21224-9
280
400
MS17826-4
30
45
MS17826-9
280
400
TORQUE WRENCHES
5 to 50 Inch-Pounds
100 to 750 Inch-Pounds
30 to 150 Inch-Pounds
END OF TASK
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