TM 55-1520-240-23-1
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STANDARD TORQUE LIMIT APPLICATION
(Continued)
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Standard Torque Limits in Inch-Pounds for Hose and Tube Coupling Nuts
TUBE OD
HOSE SIZE
NUT HEX
A
B
C
D
E
1/4
-4
9/16
105-115
135-145
50-65
135-150
100-120
3/8
-6
11/16
160-180
255-285
100-125
270-300
210-250
1/2
-8
7/8
265-295
475-525
210-250
450-500
340-420
5/8
-10
1
355-375
665-735
300-350
650-700
400-480
3/4
-12
1-1/4
430-470
855-945
425-500
900-1000
725-850
1
-16
1-1/2
715-785
600-700
1200-1400
900-1150
1-1/4
-20
2
855-945
680-800
1200-1400
950-1150
Overtightening of hose and tube coupling outs will cause thread and seal damage resulting in fitting
leakage. Torque values are for threads lubricated with hydraulic fluid (E197), antiseize compound (E75),
petrolatum (E274), or aircraft and instrument grease (E189), as applicable.
NOTE
This table not applicable to permaswage nuts coupled to Rosan fittings.
TORQUE WRENCHES
30 to 150 Inch-Pounds
700 to 1600 Inch-Pounds
100 to 750 Inch-Pounds
KEY
A Aluminum Permaswage tube coupling nuts.
B Steel Permaswage tube coupling nuts.
C Steel or aluminum flared fitting nuts, AN818, AN924, NAS591-593, and NAS594-596: used on aluminum tube1
D Steel or aluminum flared fitting nuts, AN818, AN924, NAS591-593, and NAS594-596: used on steel tube1
E Steel or aluminum flared fitting hose coupling nuts1
1Where use of a torque wrench would be difficult, use a conventional wrench to tighten coupling nuts. Tighten until a distinct increase in the
torque required is noted. Continue tightening an additional 1/6 of a turn. Back off the nut. Again tighten until a distinct increase in the torque
required is noted. Continue tightening an additional 1/6 to 1/3 of a turn.
Standard Torque Limits in Inch-Pounds for Connecting Coupling Nuts to Rosan Fittings
TUBE OD
HOSE SIZE
NUT HEX
STEEL
ALUMINUM
1/4
-4
9/16
140-150
140-150
3/8
-6
11/16
290-300
250-260
1/2
-8
7/8
525-575
410-430
5/8
-10
1
735-805
530-550
3/4
-12
1-1/4
960-1000
660-690
1
-16
1-1/2
1360-1400
1110-1150
NOTES
1. Rosan fittings are used on the following hydraulic system components:
Utility Pressure Module
Flight Control Power Control Module
Utility Return Module
Lower Controls Module
APU Start Module
ILCA Manifold
APU Start Accumulator
APU Motor Pump
Utility Cooler Reservoir
Flight Control Cooler Reservoir
2. Torque values are for fittings lubricated with hydraulic fluid (E197).
TORQUE WRENCHES
30 to 150 Inch-Pounds
700 to 1600 Inch-Pounds
100 to 750 Inch-Pounds
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