TM55-2840-251-23
APPENDIX E
TORQUE AND DIMENSIONAL LIMITS, OVERHAUL AND RETIREMENT SCHEDULE
Minimum Locking Torque Values of Self-Locking Nuts and Helical Coil Inserts.
The locking torque shall be checked at each reassembly. This check is necessary to insure that the self-locking feature
still causes a tight frictional hold on the mating threads. The locking torque shall, unless otherwise specified, be not less
than that shown in Table. When checking the self-locking torque, care must be taken to insure the fastener is unseated
so that only the torque necessary to overcome the frictional hold on the screw thread is measured. Torque values
specified are applicable only when locking torque is checked with a part similar to the intended assembly application
(size, material, coating, etc.).
Table E-1. Recommended Torque Wrench Sizes
Required Torque
Torque Wrench
0 to 25 pound-inches
30 pound-inches
(0.0 to 0.3 kg/m)
(0.3 kg/m)
25 to 140 pound-inches
150 pound-inches
(0.3 to 1.6 kg/m)
(1.7 kg/m)
140 to 550 pound-inches
600 pound-inches
(1.6 to 6.3 kg/m)
(6.9 kg/m)
30 to 140 pound-feet
150 pound-feet
(4.1 to 19.4 kg/m)
(20.7 kg/m)
140 to 240 pound-feet
250 pound-feet
(19.4 to 33.2 kg/m)
(34.6 kg/m)
240 to 1000 pound-feet
1000 pound-feet
(33.2 to 138.2 kg/m)
(138.2 kg/m)
E-1
