Check for Re-use of Self-Locking Fasteners [IAE]

TASK 70-23-11-911-011-A
Check for Re-use of Self-Locking Fasteners

1. Reason for the Job
This task gives the procedure to make sure the self-locking nuts, the bolts and the helical coil inserts (used in the engine) can be used again.
Make a test on them to make sure they will keep a specified torque capacity.
You must discard them if the lock function is not satisfactory; do not try to repair them.
2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V10-077)	lubricant (engine oil)

B. Referenced Information

REFERENCE	DESIGNATION
Torque Check for Re-use of Self-locking nuts - Bolt and Helical Coil Inserts

3. Job Set-up
Subtask 70-23-11-869-050-A ** ON A/C NOT FOR ALL

A. Not Applicable

4. Procedure
Subtask 70-23-11-911-051-A ** ON A/C NOT FOR ALL

A. Check for Re-use of Self-Locking Fasteners
(1) Torque Limit
(a) You must make sure the self-locking nuts, the bolts and the helical coil inserts agree with the necessary torque values
1 Minimum breakaway torque

This is the minimum torque necessary to initialy turn an installed nut on a bolt or a bolt in a self-locking nut or helical coil insert. The minimum breakaway torque must not be less than the value given

2 Maximum locking torque

This is the torque necessary to continuously turn a loosened nut on a bolt or a bolt in a self-locking nut or helical coil insert. The maximum locking torque must not be more than the given value

(2) Monitor the Test Procedure for the Self-Locking Nuts
(a) When you do the test on the nuts made of stainless steel, corrosion and heat resistant steel, nickel alloy and AMS6304; you must use the bolts with the dimensions as follows.
1 Use the bolts with the major, minor and pitch diameters 0.0003 in. (0.008 mm) less than the given dimensions
2 Do this for the bolt sizes of 0.190-32UNF-3A, 0.190-24UNC-3A and larger.

NOTE: The torque quantity given is measured at room temperature with the threads lubricated with V10-077lubricant (engine oil).

(3) Monitor the Test Procedure for the Unplated Nuts
(a) When you do the test on the nuts made of unplated stainless steel, corrosion resistant steel, nickel alloy and AMS6304 steel (with the threads overcut for plating at assembly) do as follows.
1 The nut threads must have a thickness of silver plate between 0.0003 in. (0.008 mm) and 0.0006 in. (0.015 mm)
2 Make sure the nuts are used with unplated bolts of the correct size and that the necessary values are used
(4) Monitor the Test Procedure for the Unplated Nuts which are not Disassembled
(a) Monitor the procedure that you use when you do a test on these unplated nuts. These nuts are always attached to the relevant assembly (for example brackets or an equivalent component) as follows.
1 Stainless steel, corrosion resistant steel, nickel alloy and AMS6304 steel nuts.
2 The nuts are not subsequently plated at assembly.
(b) When you do a test on the assembly or component do as follows.
1 The bolts you use to test the component must be silver plated to a thickness between 0.0003 in. (0.008 mm) and 0.0006 in. (0.015 mm)
2 When you use plated bolts 0.190 in. (4.83 mm) diameter or larger you must reduce the diameter, as follows.

Reduce the major, minor and thread pitch diameters 0.0003 in. (0.008 mm) from class 3A limits.

3 When you use plated bolts smaller than 0.190 in. (4.83 mm) in diameter make sure they have class 2A tolerances
(5) Monitor the Test Procedure for Unplated Carbon or Alloy Steel Nuts
(a) When you do the test on an unplated carbon or alloy steel nut do as follows:
1 Make sure the nut is cadmium plated to a thickness of between 0.0002 in. (0.005 mm) and 0.0005 in. (0.013 mm)
2 Test the nut with a cadmium plated bolt
(6) Monitor the Test Procedure for Unplated Aluminium Nuts
(a) When you do the test on an unplated aluminium nut do as follows.
1 Make sure you use a cadmium plated bolt

[Rev.10 from 2021] 2026.04.01 12:38:19 UTC