ICON A5 MM : General : Fasteners : Torque Procedure and Fastener Torque Values
Torque Procedure and Fastener Torque Values
100044-00
Nuts and bolts shall be tightened to the Final Torque values given in the table below, unless otherwise specified. In general, shear torques are used throughout the aircraft so as to limit clamping loads that could damage composite materials. Torque shall be applied to the nut, with the bolt head held motionless if possible.
Note: 
Jam nuts (e.g. AN316 checknuts) should be torqued between the Min and Max values in Table 3 (no run-on allowance).
Note: 
For small fasteners (6-32 and 4-40) not using thread locking features, such as in electrical and electronic installations, the required tightening torques are as follows: For 6-32, torque to 6-10 in-lb. For 4-40, torque to 2-4 in-lb.
Table 3. Torque Values for Specified Thread and Lock Nut. All values given are in-lbf.
Condition
Specified thread and Lock Nut
No Lubrication
Lubrication Required
Thread
Final Torque (in-lbf
Final Torque (in-lbf
#6-32
8.0-9.5
7.8-9.3
#8-32
11.3-13.3
11.1-13.1
#10-32
19.3-22.3
16.4-19.4
1/4-28
38.9-48.9
38.4-48.4
5/16-24
70.2-95.2
70.8-95.8
3/8-24
110.2-125.2
113.2-1282
7/16-20
N/A
307-337
1/2-20
N/A
338.5-458.5
9/16-18
N/A
540-660
5/8-18
N/A
705-885
Table 4. Torque Values for Specified Thread and Locking Nutplate. All values given are in-lbf.
Condition:
Specified Thread and Locking Nutplate
Nutplates, Lubrication Required
Thread
Final Torque (in-lbf
#6-32
6.5-8.0
#8-32
12.4-14.4
#10-32
25-28
1/4-28
48.7-58.7
5/16-24
77-102
Table 5. Torque Values for Specified Thread and Locking Helicoils All Values are Given in in-lbf
Condition:
Specified Thread and Locking Helicoil
Locking Helicoils, Stainless Steel Only, Applicable for Lubrication Required and no Lubrication
Thread
Final Torque (in-lbf)
#6-32
6.5-8.0
#8-32
11.5-13.5
#10-32
24-27
1/4-28
57-64
5/16-18
93-108
5/16-24
120-145
3/8-24
175-190
1/2-13
390-440
1/2-20
440-560
Note: 
Specifications within specific inspection or maintenance tasks in this manual take precedence over the general specifications given here.