TM 9-2320-363-34-2
If the maintenance procedures in Chapter 4 do not specify a tightening order, use the following
guides:
Unless otherwise specified, lubricate threads of fasteners with oil (OE/HDO-10 or OEA).
When tightening fasteners above 30 lb-ft (41 N.m), use the torque pattern but only tighten to 70
percent of final value (multiply final value by 0.7): then repeat the pattern until final value IS
reached.
Tighten circular patterns using the circular torque pattern, and straight patterns using the straight
torque pattern.
CIRCULAR TORQUE PATTERN
STRAIGHT TORQUE PATTERN
Table D-3. *Refrigerant Line Torque Specifications
Outside
Diameter of
Metal Tube
(Inch)
Torque for
Steel Tubes
lb-ft (N.m)
t
I
I
1/4
10-15 (14-20)
60-80 lb-in. (680-940 N.cm)
3/8
30-35 (41-47)
11-13 lb-ft (15-18 N.m)
1/2
30-35 (41-47)
15-20 lb-ft (20-27 N.m)
5/8
30-35 (41-47)
21-27 lb-ft (28-37 N.m)
3/4
30-35 (41-47)
28-33 lb-ft (38-45 N.m)
Torque for Aluminum
or Copper Tubes
Change 1
D-3/(D-4 Blank)
