INTRODUCTION CD3340B/YB4411
1-12
Published 04/07/2015 Control # 569-00
Table 1-8: UNC (Coarse) Thread: Torque Values for
Stainless Steel Fasteners with Oil Lubrication
NOTE: Stainless steel fasteners tend to gall while being
tightened. To reduce this risk, lubricate the threads
with oil or molybdenum disulfide and torque at low
speeds without interruptions. Do not use excessive
pressure. Impact wrenches are not recommended.
Table 1-9: Metric Coarse Thread: Torque Values for
Stainless Steel Fasteners with Oil Lubrication
NOTE: Stainless steel fasteners tend to gall while being
tightened. To reduce this risk, lubricate the threads
with oil or molybdenum disulfide and torque at low
speeds without interruptions. Do not use excessive
pressure. Impact wrenches are not recommended.
Weld Studs
Unless otherwise specified the following grade 2 torque
values (± 10%) apply.
Table 1-10: Weld Stud Torque Values
O-RING FACE SEAL (ORFS) HYDRAULIC
FITTINGS
ORFS fittings are used on the hydraulic system throughout
carrier.
ORFS (O-Ring Face Seal) fittings have a straight thread and
a flat face with an O-ring groove machined in the flat face.
Sealing takes place by compressing the O-ring onto the flat
face of the female connector.
Fittings with O-rings offer advantages over metal-to-metal
fittings. Under or overtightening any fitting can allow leakage,
but all-metal fittings are more susceptible to leakage
because they must be tightened to a higher and narrower
torque range. This makes it easier to strip threads or crack or
distort fitting components, which prevents proper sealing.
Leaks can result from vibration, thermal cycling and from
loads being supported by the connection (i.e. using the fitting
in the connection to support mechanical loads).
Recommended O-Ring Face Seal Fitting
(ORFS) Assembly Instructions
1. If installing new fittings, inspect for possible
contamination or damage from shipping or handling.
Confirm face seal O-ring is properly installed.
2. Lubricate the threads and the O-ring with your systems
hydraulic fluid or a light lubricant.
3. Align mating face seal flange against O-ring and finger
tighten face seal flange nut.
4. Torque flange nut to the value shown in the table below.
Alternate Assembly Method
1. If torque method not possible, follow steps 1-3 above,
then proceed to the steps below.
2. Lightly wrench tighten the nut until there is firm
resistance.
3. Place a wrench on wrench pad next to nut as near the 6
o’clock position as possible.
Size
Torque Value
lb-in lb-ft
#5 (0.125) 6.9 —
#8 (0.164) 18 —
#10 (0.190) 21 —
1/4 68 —
5/16 120 10
3/8 210 17.5
7/16 340 28
1/2 —39
5/8 —74
3/4 —114
Size
Torque
Value
Nm
M2.5 0.4
M3 0.9
M4 1.5
M5 3.1
M6 5.3
M8 13.0
M10 27.0
M12 45.0
M14 71.1
M16 109
M18 157
M20 220
Reference Only
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