Check for the Self-Locking Feature [PW11]

TASK 70-26-00-910-803-A
Check for the Self-Locking Feature

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

1. Reason for the Job

NOTE: Always obey the specific procedures and limits in the specific AMM maintenance tasks.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	SOCKET STANDARD
No specific	1	WRENCH - TORQUE, STANDARD

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.P03-001)	lubricant, aircraft turbine engine

C. Referenced Information

REFERENCE	DESIGNATION
Check For Self Locking Feature

3. Job Set-up
Subtask 70-26-00-869-050-A ** ON A/C NOT FOR ALL

A. Not Applicable

4. Procedure
Subtask 70-26-00-911-050-A ** ON A/C NOT FOR ALL

A. General
(1) Self-locking fasteners are designed for a limited number of reuses to keep the quality of their self-locking function. Free-spinning fasteners have other features for locking.

Check For Self Locking Feature ** ON A/C NOT FOR ALL

(2) Discard the fastener if the self-locking function is not correct.
(3) Do not pinch, squeeze or deform a fastener to repair the self-locking feature.

Subtask 70-26-00-280-050-A ** ON A/C NOT FOR ALL

B. Procedure - Feel Method
(1) Use feel to test the self-locking function of each fastener during the final assembly by the assembly mechanic.
(2) The assembly mechanic must get experience in the usual or new part feel for run-on torques of the applicable fasteners.
(3) If there is too much run-on torque, or insufficient run-on torque, during the installation of a fastener, the mechanic must replace the fastener with one which is acceptable.
(4) Discard any fastener which does not feel acceptable.

Subtask 70-26-00-280-051-A ** ON A/C NOT FOR ALL

C. Procedure - Test Method
(1) You can use a statistically valid sampling inspection program to test some of the parts as an alternative to testing every part.
(a) Use the limits in the table that follows for:
1 Self-locking nuts on bolts, screws or studs
2 Bolts or screws into self-locking helical inserts.
(b) Lubricate the fastener with P03-001lubricant, aircraft turbine engine or the applicable antigallant.
(c) Install the fastener on the mating fastener and fully engage the self-locking feature without any axial load (do not seat the fastener).
(d) Use a WRENCH - TORQUE, STANDARD and the table that follows to test the "Break Away Torque" of the fastener:
1 Install a beam or digital WRENCH - TORQUE, STANDARD and SOCKET STANDARD on the fastener.
2 Monitor the amount of torque necessary to initially start the fastener turning.
3 Compare the "Break Away Torque" indication with the limits in the table that follows.
4 Discard any fastener that is not in the limits.
(2) Use a torque wrench and the table that follows to test the "Run-On Torque" of the fastener:
(a) Install a beam or digital WRENCH - TORQUE, STANDARD and SOCKET STANDARD on the fastener.
(b) After the initial "Break Away Torque", monitor the amount of torque necessary to turn the fastener to the thread "Run-On Torque".
(c) Compare the "Run-On Torque" indication with the limits in the table that follows.
(d) Discard any fastener that is not in the limits.

Thread Size	Minimum Breakaway Torque lbf.in (m.daN)	Maximum Locking (Run- On) Torque lbf.in (m.daN)
0.112-40	0.5 lbf.in (0.006 m.daN)	3.0 lbf.in (0.034 m.daN)
0.112-48	0.5 lbf.in (0.006 m.daN)	3.0 lbf.in (0.034 m.daN)
0.138-32	1.0 lbf.in (0.011 m.daN)	6.0 lbf.in (0.068 m.daN)
0.138-40	1.0 lbf.in (0.011 m.daN)	6.0 lbf.in (0.068 m.daN)
0.164-32	1.5 lbf.in (0.017 m.daN)	9 lbf.in (0.102 m.daN)
0.164-36	1.5 lbf.in (0.017 m.daN)	9 lbf.in (0.102 m.daN)
0.190-24	2.0 lbf.in (0.023 m.daN)	13 lbf.in (0.147 m.daN)
0.190-32	2.0 lbf.in (0.023 m.daN)	13 lbf.in (0.147 m.daN)
1/4 Inch:
0.250-20	4.5 lbf.in (0.051 m.daN)	30 lbf.in (0.339 m.daN)
0.250-28	3.5 lbf.in (0.040 m.daN)	30 lbf.in (0.339 m.daN)
5/16 Inch:
0.3125-18	7.5 lbf.in (0.085 m.daN)	60 lbf.in (0.678 m.daN)
0.3125-24	6.5 lbf.in (0.073 m.daN)	60 lbf.in (0.678 m.daN)
3/8 Inch:
0.375-16	12.0 lbf.in (0.136 m.daN)	80 lbf.in (0.904 m.daN)
0.375-24	9.5 lbf.in (0.107 m.daN)	80 lbf.in (0.904 m.daN)
7/16 Inch:
0.4375-14	16.5 lbf.in (0.186 m.daN)	100 lbf.in (1.130 m.daN)
0.4375-20	14 lbf.in (0.158 m.daN)	100 lbf.in (1.130 m.daN)
1/2 Inch:
0.500-14	24 lbf.in (0.271 m.daN)	150 lbf.in (1.695 m.daN)
0.500-20	18 lbf.in (0.203 m.daN)	150 lbf.in (1.695 m.daN)
9/16 Inch:
0.5625-12	30 lbf.in (0.339 m.daN)	200 lbf.in (2.260 m.daN)
0.5625-18	24 lbf.in (0.271 m.daN)	200 lbf.in (2.260 m.daN)
5/8 Inch:
0.625-11	40 lbf.in (0.452 m.daN)	300 lbf.in (3.390 m.daN)
0.625-18	32 lbf.in (0.362 m.daN)	300 lbf.in (3.390 m.daN)
3/4 Inch:
0.750-10	60 lbf.in (0.678 m.daN)	400 lbf.in (4.520 m.daN)
0.750-16	50 lbf.in (0.565 m.daN)	400 lbf.in (4.520 m.daN)
7/8 Inch:
0.875-9	82 lbf.in (0.927 m.daN)	600 lbf.in (6.780 m.daN)
0.875-14	70 lbf.in (0.791 m.daN)	600 lbf.in (6.780 m.daN)
1 Inch:
1.000-8	110 lbf.in (1.243 m.daN)	800 lbf.in (9.040 m.daN)
1.000-14	92 lbf.in (1.040 m.daN)	800 lbf.in (9.040 m.daN)

[Rev.10 from 2021] 2026.04.02 06:31:42 UTC