| THREAD |
SIZE |
MAJOR DIAMETER MM |
THREADS PER INCH |
PITCH |
ISOMETRIC
ISOMETRIC to BS3643:1981 |
16 mm |
16 |
19.93 |
1.50 |
| 20 mm |
20 |
19.93 |
1.50 |
| 25 mm |
25 |
19.93 |
1.50 |
| 32 mm |
32 |
19.93 |
1.50 |
| 40 mm |
40 |
19.93 |
1.50 |
| 50 mm |
50 |
19.93 |
1.50 |
| 63 mm |
63 |
19.93 |
1.50 |
| 75 mm |
75 |
19.93 |
1.50 |
P.G.
P.G. to DIN 40430:1971 |
PG 7 |
12.50 |
20 |
1.27 |
| PG 9 |
15.20 |
18 |
1.41 |
| PG 11 |
18.60 |
18 |
1.41 |
| PG 13.5 |
20.40 |
18 |
1.41 |
| PG 16 |
22.50 |
18 |
1.41 |
| PG 21 |
28.30 |
16 |
1.59 |
| PG 29 |
37.00 |
16 |
1.59 |
| PG 36 |
47.00 |
16 |
1.59 |
| PG 42 |
54.00 |
16 |
1.59 |
| PG 48 |
59.30 |
16 |
1.59 |
IMPERIAL
IMPERIAL to BS31:1940 (1979) |
5/8"
|
15.88 |
18 |
1.41 |
| 3/4" |
19.05 |
16 |
1.59 |
| 1" |
25.40 |
16 |
1.59 |
| 1.1/4" |
31.75 |
16 |
1.59 |
| 1.1/2" |
38.10 |
14 |
1.81 |
| 2" |
50.80 |
14 |
1.81 |
| 2.1/2" |
63.50 |
14 |
1.81 |
| 3" |
76.20 |
14 |
1.81 |
N.P.T.
NATIONAL PIPE THREAD to ANSI/ASME:1983 |
1/8" |
10.30 |
27 |
0.94 |
| 1/4" |
13.72 |
18 |
1.41 |
| 3/8" |
17.15 |
18 |
1.41 |
| 1/2" |
21.34 |
14 |
1.81 |
| 3/4" |
26.67 |
14 |
1.81 |
| 1" |
33.40 |
12 |
2.20 |
| 1.1/4" |
42.16 |
12 |
2.20 |
| 1.1/2" |
48.26 |
12 |
2.20 |
| 2" |
60.33 |
12 |
2.20 |
| 2.1/2" |
73.03 |
8 |
3.175 |
| 3" |
88.90 |
8 |
3.175 |
| 4" |
114.30 |
8 |
3.175 |
B.S.P.
BRITISH STANDARD
PIPE to BS21:1985 |
1/8" |
9.73 |
28 |
0.91 |
| 1/4" |
13.16 |
19 |
1.34 |
| 3/8" |
16.66 |
19 |
1.34 |
| 1/2" |
20.96 |
14 |
1.81 |
| 5/8" |
22.91 |
14 |
1.81 |
| 3/4" |
26.44 |
14 |
1.81 |
| 1" |
33.25 |
11 |
2.31 |
| 1.1/4" |
41.91 |
11 |
2.31 |
| 1.1/2" |
47.80 |
11 |
2.31 |
| 2" |
59.61 |
11 |
2.31 |
| 2.1/2" |
75.18 |
11 |
2.31 |
| 3" |
87.88 |
11 |
2.31 |
| 4" |
113.03 |
11 |
2.31 |
