Hydraulic adapters and malleable iron fittings are identified with number codes representing each size, while brass pipe thread fittings use letter codes to represent each size. Both systems are commonly used throughout the industry.
Nominal Thread Size (Inches) |
SAE Number Dash Sizes |
NPT Letter Dash Sizes |
Fraction Size |
---|---|---|---|
1/16 |
1 |
|
0.0625 |
1/8 |
2 |
A |
0.1250 |
3/16 |
3 |
|
0.1875 |
1/4 |
4 |
B |
0.2500 |
5/16 |
5 |
|
0.3125 |
3/8 |
6 |
C |
0.3750 |
1/2 |
8 |
D |
0.5000 |
5/8 |
10 |
|
0.6250 |
3/4 |
12 |
E |
0.7500 |
7/8 |
14 |
|
0.8750 |
1 |
16 |
F |
1.000 |
1 1/4 |
20 |
G |
1.250 |
1 1/2 |
24 |
H |
1.500 |
2 |
32 |
I |
2.000 |
2 1/2 |
40 |
J |
2.500 |
3 |
48 |
K |
3.000 |
4 |
64 |
L |
4.000 |
Note: In the case of a fitting that is a jump size, it is recommended that the lower pressure of the two ends must be recognized as the working pressure
rating for that fitting. This is also the case if the fitting has one or more different style ends. For example, straight threads to pipe threads. In this case
it is also recommended that the lower pressure rating of the two different style ends must be recognized as the working pressure rating for that fitting.
Nom SAE Dash Size |
Nom Tube O.D. in MM |
Nom Tube O.D. in Inch |
Straight Thread Size |
Nom Pipe Size |
Rigid SAE St. Thread Unions & Bulkhead MPa |
Rigid SAE St. Thread Unions & Bulkhead PSI |
Adjustable SAE Std. Thread & Female Swivel MPa |
Adjustable SAE Std. Thread & Female Swivel PSI |
Fittings with Pipe Thread MPa |
Fittings with Pipe Thread PSI |
NPSM Std. Pipe Thread Maximum Operating Pressure MPa |
NPSM Std. Pipe Thread Maximum Operating Pressure MPA |
---|---|---|---|---|---|---|---|---|---|---|---|---|
2 |
3.18 |
0.250 |
5/16 24 |
1/8 |
34.5 |
5,000 |
34.5 |
5,000 |
34.5 |
5,000 |
34.5 |
5,000 |
3 |
4.76 |
0.188 |
3/8 24 |
1/8 |
34.5 |
5,000 |
34.5 |
5,000 |
34.5 |
5,000 |
|
|
4 |
6.35 |
0.250 |
7/16 20 |
1/8 |
34.5 |
5,000 |
31.0 |
4,500 |
34.5 |
5,000 |
34.5 |
5,000 |
5 |
7.94 |
0.313 |
1/2 20 |
1/8 |
34.5 |
5,000 |
27.5 |
4,000 |
34.5 |
5,000 |
|
|
6 |
9.52 |
0.375 |
9/16 18 |
1/4 |
34.5 |
5,000 |
27.5 |
4,000 |
27.5 |
4,000 |
27.5 |
4,000 |
8 |
12.70 |
0.500 |
3/4 16 |
3/8 |
31.0 |
4,500 |
27.5 |
4,000 |
21.0 |
3,000 |
24.1 |
3,500 |
10 |
15.88 |
0.625 |
7/8 14 |
1/2 |
24.0 |
3,500 |
21.0 |
3,000 |
21.0 |
3,000 |
|
|
12 |
19.05 |
0.750 |
1 1/16 12 |
3/4 |
24.0 |
3,500 |
21.0 |
3,000 |
17.0 |
2,500 |
15.5 |
2,250 |
14 |
22.22 |
0.875 |
1 3/16 12 |
3/4 |
21.0 |
3,000 |
17.0 |
2,500 |
17.0 |
2,500 |
|
|
16 |
25.40 |
1.000 |
1 5/16 12 |
1 |
21.0 |
3,000 |
17.0 |
2,500 |
14.0 |
2,000 |
13.8 |
2,000 |
20 |
31.75 |
1.250 |
1 5/8 12 |
1 1/4 |
17.0 |
2,500 |
14.0 |
2,500 |
8.0 |
1,150 |
11.2 |
1,625 |
24 |
38.10 |
1.500 |
1 7/8 12 |
1 1/2 |
14.0 |
2,000 |
10.5 |
1,500 |
7.0 |
1,000 |
8.6 |
1,250 |
32 |
50.30 |
2.000 |
2 1/2 12 |
2 |
10.5 |
1,500 |
8.0 |
1,125 |
7.0 |
1,000 |
7.8 |
1,125 |