Metric threads (60° thread angle, general-purpose threads) / DIN 3852, ISO 6149
| M |
d2 |
d3 Minimum |
d4 |
d5 |
a1 Maximum |
t2 |
t1 Minimum |
b1 Minimum |
α±1° |
| M8*1 |
10.9 |
17 |
11 |
9.1 |
1.0 |
1.6 |
11.5 |
10.0 |
12° |
| M10*1 |
12.9 |
20 |
13 |
11.1 |
1.0 |
1.6 |
11.5 |
10.0 |
12° |
| M12*1.5 |
16.9 |
22 |
16 |
13.8 |
1.5 |
2.4 |
14.0 |
11.5 |
15° |
| M14*1.5 |
18.9 |
25 |
18 |
15.8 |
1.5 |
2.4 |
14.0 |
11.5 |
15° |
| M16*1.5 |
20.9 |
27 |
20 |
17.8 |
1.5 |
2.4 |
15.5 |
13.0 |
15° |
| M18*1.5 |
22.9 |
29 |
22 |
19.8 |
2.0 |
2.4 |
16.5 |
14.5 |
15° |
| M20*1.5 |
24.9 |
32 |
24 |
21.8 |
2.0 |
2.4 |
16.5 |
14.0 |
15° |
| M22*1.5 |
26.9 |
34 |
26 |
23.8 |
2.0 |
2.4 |
18.0 |
15.5 |
15° |
| M26*1.5 |
30.9 |
37 |
31 |
29.1 |
2.0 |
3.1 |
18.5 |
16.0 |
15° |
| M27*2 |
31.9 |
40 |
32 |
29.4 |
2.0 |
3.1 |
22.0 |
19.0 |
15° |
| M33*2 |
37.9 |
46 |
38 |
35.4 |
2.5 |
3.1 |
22.0 |
19.0 |
15° |
| M42*2 |
47.9 |
56 |
47 |
44.4 |
2.5 |
3.1 |
22.5 |
19.5 |
15° |
| M48*2 |
54.9 |
64 |
53 |
50.4 |
2.5 |
3.1 |
25.0 |
22.0 |
15° |
American UNF/UN threads (60° thread angle) / SAE J 514, ISO 11926
| U |
d2 |
d3 Minimum |
d4 |
d5+0.1 |
a1 Maximum |
t2 |
t1 Minimum |
b1 Minimum |
α±1° |
| 7/16-20UNF |
14.4 |
21 |
15 |
12.4 |
1.6 |
2.4 |
14.0 |
11.5 |
12° |
| 9/16-18UNF |
17.6 |
25 |
18 |
15.6 |
1.6 |
2.5 |
15.5 |
12.7 |
12° |
| 3/4-16UNF |
22.3 |
30 |
23 |
20.6 |
2.4 |
2.5 |
17.5 |
14.3 |
15° |
| 7/8-14UNF |
25.5 |
34 |
26 |
23.9 |
2.4 |
2.5 |
20.0 |
16.7 |
15° |
| 11/16-12UN |
31.9 |
41 |
32 |
29.2 |
2.4 |
3.3 |
23.0 |
19.0 |
15° |
| 15/16-12UN |
38.2 |
49 |
39 |
35.5 |
3.2 |
3.3 |
23.0 |
19.0 |
15° |
| 15/8-12UN |
47.7 |
58 |
48 |
43.5 |
3.2 |
3.3 |
23.0 |
19.0 |
15° |
55° sealed tapered pipe thread (ISO 7-1), imperial R external thread and Rc internal thread (formerly known as PT thread and ZG thread)
| R |
t3 Minimum |
t4 Minimum |
t5 Minimum |
Withstand voltage bar |
| R1/8″ |
11.1 |
7.5 |
6.5 |
360 |
| R1/4″ |
15.1 |
11.1 |
9.7 |
360 |
| R3/8″ |
15.5 |
11.5 |
10.1 |
360 |
| R1/2″ |
19.6 |
15.1 |
13.2 |
360 |
| R3/4″ |
21.0 |
16.4 |
14.5 |
350 |
| R1″ |
24.2 |
19.2 |
16.8 |
320 |
| R11/4″ |
26.5 |
21.5 |
19.1 |
310 |
| R11/2″ |
26.5 |
21.5 |
19.1 |
280 |
| R2″ |
31.0 |
26.0 |
23.4 |
280 |
60° sealed tapered pipe thread, American NPT thread (for NPTF dry-seal threads, please inquire)
| NPT |
t3 Minimum |
t4 Minimum |
t5 Minimum |
Withstand voltage Bar |
| 1/8-27 |
11.6 |
8.0 |
7.0 |
420 |
| 1/4-18 |
15.5 |
11.5 |
10.0 |
420 |
| 3/8-18 |
15.8 |
11.8 |
10.4 |
420 |
| 1/2-14 |
20.0 |
15.5 |
13.6 |
420 |
| 3/4-14 |
20.5 |
16.0 |
14.1 |
350 |
| 1-11.5 |
24.0 |
19.0 |
16.8 |
320 |
| 11/4-11.5 |
24.5 |
19.5 |
17.3 |
280 |
| 11/2-11.5 |
24.5 |
19.5 |
17.3 |
250 |
Pressure gauge threaded connection (GB/T 1226-2001)
| d |
L(mm) |
d1(mm) |
| M10*1 |
10 |
4 |
| M14*1.5 |
14 |
5 |
| M20*1.5 |
20 |
6 |
