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
