Datasheet

Connection Thread Tightening Method
5. Face seal fittings: R, NPT, G
1) Tighten fittings with sealant using the proper tightening
torques in the table below.
2) Insufficient tightening may cause seal failure, or loosen the
threads.
3) Reuse
(1) Normally, fittings with a sealant can be reused up to 6 to
10 times.
(2) The seal ring cannot be replaced.
Connection thread size
(R, NPT, G)
Proper tightening torque
[N·m]
1/16, 1/8 3 to 5
1/4 8 to 12
3/8 15 to 20
1/2 20 to 25
Ø D
45°
Caution
1. Chamfer dimension for female thread of the
connection thread M3, M5, 10-32UNF
Confi rming to ISO 16030 (air pressure fl uid dynamics – connection
– ports and stud ends), the chamfer dimensions shown below are
recommended. By chamfering as shown in the following table,
machining of threads is easier and effective for burr prevention.
Chamfer Dimension for Female Thread
Connection
thread size
Chamfer dimension Ø D
(Recommended value)
[mm]
M3 3.1 to 3.4
M5 5.1 to 5.4
10-32UNF 5.0 to 5.3
Connection Female Thread: Rc, NPT, NPTF
Connection Female Thread: G
2) The gasket can be reused up to 6 to 10 times. It can be replaced
easily when it has sustained damage. A broken gasket can be
removed by holding it and then turning it in the same direction as
loosening the thread. If gasket is diffi cult to remove, cut it with nippers,
etc. In such a case, use caution not to scratch the seat face because
the seat face of 45° gasket of fi tting is the sealing face.
6. Uni thread fi ttings
1) First, tighten the threaded portion by hand, then use a proper wrench,
which could be suitable for the width across flats of the hexagon
body, to tighten it further at a wrench tightening angle shown below.
As a reference value for the tightening torque, refer to the table below.
Uni thread size
Wrench tightening angle
after hand-tightening
[deg]
Tightening torque
[N·m]
1/8 30 to 45 3 to 4
1/4 15 to 30 4 to 5
3/8 15 to 30 8 to 9
1/2 15 to 30 14 to 15
Uni thread size
Wrench tightening angle
after hand-tightening
[deg]
Tightening torque
[N·m]
1/8 30 to 60 3 to 5
1/4 30 to 60 8 to 12
3/8 15 to 45 14 to 16
1/2 15 to 30 20 to 22
Fittings & Tubing
Precautions 4
Be sure to read this before handling products.
2) If the fitting is tightened with excessive torque, a large
amount of sealant will seep out. Remove the excess sealant.
3) Insuffi cient tightening may cause seal failure, or loosen the
threads.
4) Reuse
(1) Normally, fi ttings with a sealant can be reused up to 2 to
3 times.
(2) To prevent air leakage through the sealant, remove any
loose sealant stuck to the fi tting by blowing air over the
threaded portion.
(3) If the sealant no longer provides effective sealing, wind
sealing tape over the sealant before reusing. Do not use
the sealant in any form other than a tape type.
(4) Once the fi tting has been tightened, backing it out to its
original position often causes the sealant to become
defective. Air leakage will occur.
Connection thread size
(R, NPT)
Tightening torque
[N·m]
1/16, 1/8 3 to 5
1/4 8 to 12
3/8 15 to 20
1/2 20 to 25
45°
Rz 12.5
Ø D
2. Chamfer dimension of R and
NPT thread with sealant, and
Uni thread
Connection
thread size
Chamfer dimension Ø D (Recommended value)
G Rc NPT, NPTF
1/16 — — 8.2 to 8.4
1/8 10.2 to 10.6 10.2 to 10.4 10.5 to 10.7
1/4 13.6 to 14.0 13.6 to 13.8 14.1 to 14.3
3/8 17.1 to 17.5 17.1 to 17.3 17.4 to 17.6
1/2 21.4 to 21.8 21.4 to 21.6 21.7 to 21.9
1. Connection thread: M3
First, tighten by hand, then use a wrench appropriate for the
hexagon fl ats of the body to tighten an additional 1/4 turn.
A reference value for the tightening torque is 0.4 to 0.5 N·m.
2. Connection thread: M5 and 10-32UNF
First, tighten by hand, then use a wrench appropriate for the
hexagon fl ats of the body to tighten an additional 1/6 to 1/4 turn.
A reference value for the tightening torque is 1 to 1.5 N·m.
3. Connection thread: M6
First, tighten by hand, then use a wrench appropriate for the
hexagon fl ats of the body to tighten an additional 1/6 to 1/4 turn.
∗ Excessive tightening may damage the thread portion or
deform the gasket and cause air leakage.
Insuffi cient tightening may loosen the threads, or cause air
leakage.
4. Fittings with sealant: R, NPT
1) First, tighten the fitting by hand, then use a wrench
appropriate for the hexagon fl ats of the body to tighten it a
further two or three turns.
For a tightening torque guide, see the table below.
∗
For Uni thread, Rz 12.5 is necessary for sealing at the chamfered part.
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