标准：摘自GB/T 7307-1987 等效ISO228/1-1982
| 尺寸代号 |
每25.4(mm)内的牙数n |
螺距p |
牙高h |
圆弧半径r |
基面上的直径\大径d=D |
基面上的直径\中径d2=D2 |
基面上的直径\小径d1=D1 |
| 1/16 |
28 |
0.907 |
0.581 |
0.125 |
7.723 |
7.142 |
6.561 |
| 1/8 |
28 |
0.907 |
0.581 |
0.125 |
9.728 |
9.147 |
8.566 |
| 1/4 |
19 |
1.337 |
0.856 |
0.184 |
13.157 |
12.301 |
11.445 |
| 3/8 |
19 |
1.337 |
0.856 |
0.184 |
16.662 |
15.806 |
14.95 |
| 1/2 |
14 |
1.814 |
1.162 |
0.249 |
20.955 |
19.793 |
18.631 |
| 5/8 |
14 |
1.814 |
1.162 |
0.249 |
22.911 |
21.749 |
20.587 |
| 3/4 |
14 |
1.814 |
1.162 |
0.249 |
26.441 |
25.279 |
24.117 |
| 7/8 |
14 |
1.814 |
1.162 |
0.249 |
30.201 |
29.039 |
27.877 |
| 1 |
11 |
2.309 |
1.479 |
0.317 |
33.249 |
31.77 |
30.291 |
| 1+1/3 |
11 |
2.309 |
1.479 |
0.317 |
37.897 |
36.418 |
34.939 |
| 1+1/4 |
11 |
2.309 |
1.479 |
0.317 |
41.91 |
40.431 |
38.952 |
| 1+1/2 |
11 |
2.309 |
1.479 |
0.317 |
47.803 |
46.324 |
44.845 |
| 1+3/4 |
11 |
2.309 |
1.479 |
0.317 |
53.746 |
52.267 |
50.788 |
| 2 |
11 |
2.309 |
1.479 |
0.317 |
59.614 |
58.135 |
56.656 |
| 2+1/4 |
11 |
2.309 |
1.479 |
0.317 |
65.71 |
64.231 |
62.752 |
| 2+1/2 |
11 |
2.309 |
1.479 |
0.317 |
75.184 |
73.705 |
72.226 |
| 2+3/4 |
11 |
2.309 |
1.479 |
0.317 |
81.534 |
80.055 |
78.576 |
| 3 |
11 |
2.309 |
1.479 |
0.317 |
87.884 |
86.405 |
84.926 |
| 3+1/2 |
11 |
2.309 |
1.479 |
0.317 |
100.33 |
98.851 |
97.372 |
| 4 |
11 |
2.309 |
1.479 |
0.317 |
113.03 |
111.551 |
110.072 |
| 5 |
11 |
2.309 |
1.479 |
0.317 |
138.43 |
136.951 |
135.472 |
| 5+1/2 |
11 |
2.309 |
1.479 |
0.317 |
151.13 |
149.651 |
148.172 |
| 6 |
11 |
2.309 |
1.479 |
0.317 |
163.83 |
162.351 |
160.872 |
1.对薄壁管件、中径公差适用于平均中径，该中径是测量两个相垂直直径的算术平均值。
2.本标准适用于管接头、旋塞、阀门及其附件。
3.标记示例：
螺纹特征代号用G表示
1 1/2左旋内螺纹： G1 1/2-LH（右旋不标）；
1 1/2A级外螺纹：G1 1/2A
1 1/2B级外螺纹：G1 1/2B
A级螺纹副：G1 1/2 / G1 1/2A
4.在示图
中：
p = 25.4 / n
h = 0.640327p
H = 0.960491p
r = 0.137329p
