Fluid Port Size Charts
The tables below may help you identify the correct fittings for your application.
Please note that Nominal Size (1/2" JIC or 1/2" NPTF, for example) frequently refers to the I.D. of the pipe or the O.D. of the tubing for which that fitting is intened. This should not be confused with the dimension of the thread, which is nearly always larger than nominal tube or pipe size.
National Pipe Tapered Fuel (NPTF)
Dash Size |
Nominal Size
(Pipe I.D.)
|
Nominal Thread Size |
Male Thread
(O.D.) |
Female Thread (I.D.) |
-02 |
1/8" |
1/8-27 |
13/32" (0.41) |
3/8" (0.38) |
-04 |
1/4" |
1/4-18 |
17/32" (0.54) |
1/2" (0.49) |
-06 |
3/8" |
3/8-18 |
11/16" (0.68) |
5/8" (0.63) |
-08 |
1/2" |
1/2-14 |
27/32" (0.84) |
25/32" (0.77) |
-12 |
3/4" |
3/4-14 |
1 1/16" (1.05) |
1" (0.98) |
-16 |
1" |
1-11.5 |
1 5/16" (1.32) |
1 1/4" (1.24) |
-20 |
1 1/4" |
1 1/4-11.5 |
1 21/32" (1.66) |
1 19/32" (1.58) |
-24 |
1 1/2" |
1 1/2-11.5 |
1 29/32" (1.90) |
1 13/16" (1.82) |
-32 |
2" |
2-11.5 |
2 3/8" (2.38) |
2 5/16" (2.30) |
NPTF fittings are still widely used, even though they are not recommended by the National Fluid Power Association (NFPA) for use in hydraulic applications. The thread is tapered and the seal takes place by deformation of the threads. Measure thread diameter and subtract one quarter-inch to find the nominal pipe size.
National Pipe Straight Mechanical (NPSM)
Thread dimensions are the same as NPTF (above). The female fitting has a parallel thread and an inverted 30° seat. The male fitting has a parallel thread and a 30° internal chamfer.
The seal takes place by compression of the seat on the chamfer. The threads hold the connection mechanically.
A properly chamfered NPTF male will also seal with the NPSM female.
JIC 37° Hydraulic (SAE J514)
Dash Size |
Nominal Size
(Tube O.D.)
|
Nominal Thread Size |
Male Thread
(O.D.) |
Female Thread (I.D.) |
| -02 |
1/8" |
5/16-24 |
5/16" (0.31) |
9/32" (0.27) |
| -03 |
3/16" |
3/8-24 |
3/8" (0.38) |
11/32" (0.34) |
| -04 |
1/4" |
7/16-20 |
7/16" (0.44) |
13/32" (0.39) |
| -05 |
5/16" |
1/2-20 |
1/2" (0.50) |
15/32" (0.45) |
| -06 |
3/8" |
9/16-18 |
9/16" (0.56) |
17/32" (0.51) |
| -08 |
1/2" |
3/4-16 |
3/4" (0.75) |
11/16" (0.69) |
| -10 |
5/8" |
7/8-14 |
7/8" (0.88) |
13/16" (0.81) |
| -12 |
3/4" |
1 1/16-12 |
1 1/16" (1.06) |
1" (0.98) |
| -14 |
7/8" |
1 3/16-12 |
1 3/16" (1.19) |
1 1/8" (1.10) |
| -16 |
1" |
1 5/16-12 |
1 5/16" (1.31) |
1 1/4" (1.23) |
| -20 |
1 1/4" |
1 5/8-12 |
1 5/8" (1.63) |
1 9/16 (1.54) |
| -24 |
1 1/2" |
1 7/8-12 |
1 7/8" (1.88) |
1 13/16" (1.79) |
| -32 |
2" |
2 1/2-12 |
2 1/2-12" (2.50) |
2 7/16" (2.42) |
JIC fittings are very common in fluid power applications. Both the male and female fittings have 37° seat. The seal takes place between the male flare and female cone seat. The threads hold the connection mechanically.
45° Flare (SAE J512)
Dash Size |
Nominal Size
(Tube O.D.)
|
Nominal Thread Size |
Male Thread
(O.D.) |
Female Thread (I.D.) |
| -02 |
1/8" |
5/16-24 |
5/16" (0.31) |
9/32" (0.27) |
| -03 |
3/16" |
3/8-24 |
3/8" (0.38) |
11/32" (0.34) |
| -04 |
1/4" |
7/16-20 |
7/16" (0.44) |
13/32" (0.39) |
| -05 |
5/16" |
1/2-20 |
1/2" (0.50) |
15/32" (0.45) |
| -06 |
3/8" |
5/8-18 |
5/8" (0.63) |
9/16" (0.57) |
| -08 |
1/2" |
3/4-16 |
3/4" (0.75) |
11/16" (0.69) |
| -10 |
5/8" |
7/8-14 |
7/8" (0.88) |
13/16" (0.81) |
| -12 |
3/4" |
1 1/16-14 |
1 1/16" (1.06) |
1" (0.99) |
| -14 |
7/8" |
1 3/16-12 |
1 3/16" (1.19) |
1 1/8" (1.10) |
| -16 |
1" |
1 5/16-12 |
1 5/16" (1.31) |
1 1/4" (1.23) |
SAE 45° Flare is a common connection in refrigeration, automotive and truck piping systems. The fittings are frequently made of brass. Both the male and female fittings have 45° seat. The seal takes place between the male flare and female cone seat. The threads hold the connection mechanically.
Straight Thread O-Ring Boss (SAE J514)
Dash Size |
Nominal Size
(common reference)
|
Nominal Thread Size |
Male Thread
(O.D.) |
Female Thread (I.D.) |
| -02 |
SAE #2 |
5/16-24 |
5/16" (0.31) |
9/32" (0.27) |
| -03 |
SAE #3 |
3/8-24 |
3/8" (0.38) |
11/32" (0.34) |
| -04 |
SAE #4 |
7/16-20 |
7/16" (0.44) |
13/32" (0.39) |
| -05 |
SAE #5 |
1/2-20 |
1/2" (0.50) |
15/32" (0.45) |
| -06 |
SAE #6 |
9/16-18 |
9/16" (0.56) |
17/32" (0.51) |
| -08 |
SAE #8 |
3/4-16 |
3/4" (0.75) |
11/16" (0.69) |
| -10 |
SAE #10 |
7/8-14 |
7/8" (0.88) |
13/16" (0.81) |
| -12 |
SAE #12 |
1 1/16-12 |
1 1/16" (1.06) |
1" (0.98) |
| -14 |
SAE #14 |
1 3/16-12 |
1 3/16" (1.19) |
1 1/8" (1.10) |
| -16 |
SAE #16 |
1 5/16-12 |
1 5/16" (1.31) |
1 1/4" (1.23) |
| -20 |
SAE #20 |
1 5/8-12 |
1 5/8" (1.63) |
1 9/16 (1.54) |
| -24 |
SAE #24 |
1 7/8-12 |
1 7/8" (1.88) |
1 13/16" (1.79) |
| -32 |
SAE #32 |
2 1/2-12 |
2 1/2-12" (2.50) |
2 7/16" (2.42) |
Straight Thread ORB is recommended by the NFPA for optimal leakage control in medium and high pressure hydraulic systems. The male fitting has a straight thread and O-ring. The female port has a straight thread, a machined surface (minimum spotface) and a chamfer to accept the O-ring. The seal take place by compressing the O-ring in the chamfer. The threads hold the connection mechanically.
Ermeto Flareless Tube Fittings (SAE J514)
Dash Size |
Nominal Size
(Tube O.D.)
|
Nominal Thread Size |
Male Thread
(O.D.) |
Female Thread (I.D.) |
-02 |
1/8" |
5/16-24 |
5/16" (0.31) |
9/32" (0.27) |
-03 |
3/16" |
3/8-24 |
3/8" (0.38) |
11/32" (0.34) |
-04 |
1/4" |
7/16-20 |
7/16" (0.44) |
13/32" (0.39) |
-05 |
5/16" |
1/2-20 |
1/2" (0.50) |
15/32" (0.45) |
-06 |
3/8" |
9/16-18 |
9/16" (0.56) |
17/32" (0.51) |
-08 |
1/2" |
3/4-16 |
3/4" (0.75) |
11/16" (0.69) |
-10 |
5/8" |
7/8-14 |
7/8" (0.88) |
13/16" (0.81) |
-12 |
3/4" |
1 1/16-12 |
1 1/16" (1.06) |
1" (0.98) |
-14 |
7/8" |
1 3/16-12 |
1 3/16" (1.19) |
1 1/8" (1.10) |
-16 |
1" |
1 5/16-12 |
1 5/16" (1.31) |
1 1/4" (1.23) |
-20 |
1 1/4" |
1 5/8-12 |
1 5/8" (1.63) |
1 9/16 (1.54) |
-24 |
1 1/2" |
1 7/8-12 |
1 7/8" (1.88) |
1 13/16" (1.79) |
-32 |
2" |
2 1/2-12 |
2 1/2-12" (2.50) |
2 7/16" (2.42) |
The male flareless fitting has straight threads and a 24° seat. The female connection uses a tube, tube nut, and bite-type sleeve. When the tube nut is tightened the seal is made between the sleeve and 24° seat. A seal is also made between the sleeve and the tubing. The threads hold the connection mechanically.
O-Ring Face Seal (SAE J5143)
Dash Size |
Nominal Size
(Tube O.D.)
|
Nominal Thread Size |
Male Thread
(O.D.) |
Female Thread (I.D.) |
| -04 |
1/4" |
9/16-18 |
9/16" (0.56) |
17/13" (0.51) |
| -06 |
3/8" |
11/16-16 |
11/16" (0.69) |
5/8" (0.63) |
| -08 |
1/2" |
13/16-16 |
13/16" (0.82) |
3/4" (0.75) |
| -10 |
5/8" |
1-14 |
1" (1.00) |
15/16" (0.93) |
| -12 |
3/4" |
1 3/16-12 |
1 3/16" (1.19) |
1 1/8" (1.11) |
| -16 |
1" |
1 7/16-12 |
1 7/16" (1.44) |
1 3/8" (1.36) |
| -20 |
1 1/4" |
1 11/16-12 |
1 11/16" (1.69) |
1 5/8" (1.61) |
| -24 |
1 1/2" |
2-12 |
2" (2.00) |
1 15/16" (1.92) |
O-Ring Face Seal (ORFS) provides the best leak protection available today. The male fitting has a straight thread and O-ring in the face. The female has a straight thread and a machined flat face. The seal takes places by compressing the O-ring onto the flat face of the female, similar to a split flange fitting. The threads hold the connection mechanically.
Four-Bolt Flanges (SAE J518)
Dash
Size |
Nominal
Port Size |
Code 61
Flange Head (O.D.) |
Code 61
Bolt Hole Spacing
|
Code 62
Flange Head (O.D.) |
Code 62
Bolt Hole Spacing |
| -08 |
1/2" |
1 3/16" (1.19) |
1 1/2" (1.50) |
1 1/4" (1.25) |
1 19/32" (1.59) |
| -12 |
3/4" |
1 1/2" (1.50) |
1 7/8" (1.88) |
1 5/8" (1.63) |
2" (2.00) |
| -16 |
1" |
1 3/4" (1.75) |
2 1/16" (2.06) |
1 7/8" (1.88) |
2 1/4" (2.25) |
| -20 |
1 1/4" |
2" (2.00) |
2 5/16" (2.31) |
2 1/8" (2.13 |
2 5/8" (2.63) |
| -24 |
1 1/2" |
2 3/8" (2.38) |
2 3/4" (2.75) |
2 1/2" (2.50) |
3 1/8" (3.13) |
| -32 |
2" |
3 1/16" |
3 1/16" (3.06) |
3 1/8" (3.13) |
3 13/16" (3.81) |
SAE flanges are available in two pressure ratings. Code 61 is intended for for pressures up to 3,000 psi. Code 62 is intended for up to 6,000 psi. Bolt hole spacing and flange head diameters are larger for the higher pressure Code 62 fittings.
The female port is an unthreaded hole with four bolt holes in a rectangular pattern around the port. The male fitting is a flanged head, grooved for an O-ring, and either a captive flange or split flange halves with bolt holes to match the port. The seal takes place by compressing the O-ring between the flanged head and the flat surface surrounding the port. The threaded bolts hold the connection together.
British Standard Pipe (BSPP/BSPT)
Dash Size |
Nominal Size
(Pipe I.D.)
|
Nominal Thread Size* |
Male Thread
(O.D.) |
Female Thread (I.D.) |
| -02 |
1/8" |
1/8-28 |
3/8" (0.38) |
11/32" (0.35) |
| -04 |
1/4" |
1/4-19 |
33/64" (0.52) |
15/32" (0.47) |
| -06 |
3/8" |
3/8-19 |
21/32" (0.65) |
19/32" (0.60) |
| -08 |
1/2" |
1/2-14 |
13/16" (0.82) |
3/4" (0.75) |
| -10 |
5/8" |
5/8-14 |
7/8" (0.88) |
13/16" (0.80) |
| -12 |
3/4" |
3/4-14 |
1 1/32 (1.04) |
31/32" (0.97) |
| -16 |
1" |
1-11 |
1 5/16" (1.30) |
1 7/32" (1.22) |
| -20 |
1 1/4" |
1 1/4-11 |
1 21/32" (1.65) |
1 5/16" (1.56) |
| -24 |
1 1/2" |
1 1/2-11 |
1 7/8" (1.88) |
1 25/32" (1.79) |
| -23 |
2" |
2-11 |
2 11/32" (2.35) |
2 1/4" (2.26) |
The BSPT (tapered) connection is similar to NPT or NPTF, except the thread pitches are different in most sizes, and the thread and O.D. are close, but not the same. Sealing is accomplished by thread distortion. A thread sealant is recommended.
The BSPP (parallel) connection is similar to NPSM, except the thread pitches are different in most sizes. The female swivel BSPP has a tapered nose/Globeseal flareless swivel which seals on the cone seat of the male.
* Frequently, the thread size is expressed as a fractional dimension preceded by the letter "G" (parallel thread) or "R" (tapered thread). For example, BSPP 1/2-14 may be expressed as G1/2, and BSPT 1/2-19 may be expressed as R1/2.
Metric Tube Fittings (DIN 3902 Series)
Tube O.D. L.RH
(Light Series)
|
Tube O.D. S.RH
(Heavy Series) |
Metric
Thread Size
|
Male
Thread
(O.D.) |
Female Thread
(I.D.) |
| 6 mm |
|
M12x1,5 |
12 mm |
10,5 mm |
| 8 mm |
6 mm |
M14x1,5 |
14 mm |
12,5 mm |
| 10 mm |
8 mm |
M16x1,5 |
16 mm |
14,5 mm |
| 12 mm |
10 mm |
M18x1,5 |
18 mm |
16,5 mm |
| |
12 mm |
M20x1,5 |
20 mm |
18,5 mm |
| 15 mm |
14 mm |
M22x1,5 |
22 mm |
20,5 mm |
| |
16 mm |
M24x1,5 |
24 mm |
22,5 mm |
| 18 mm |
|
M26x1,5 |
26 mm |
24,5 mm |
| 22 mm |
20 mm |
M30,2,0 |
30 mm |
28 mm |
| 28 mm |
25 mm |
M36x2,0 |
36 mm |
34 mm |
| |
30 mm |
M42x2,0 |
42 mm |
40 mm |
| 35 mm |
|
M45x2,0 |
45 mm |
43 mm |
| 42 mm |
38 mm |
M52x2,0 |
52 mm |
50 mm |
The DIN 3902 connection consists of a common male and three different female fittings.
Themale has a straight metric thread, a 24° included angle and a recessed counterbore the matches the tube O.D. used with it. The female maybe a tube with nute and ferrule, a tapered nose/Gloveseal flareless swivel or a tapered nose/Gloveseal flareless swivel with an O-Ring in the nose (DKO type).
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