-
英制管螺纹基本尺寸及公差（牙形角
55
?）
BSPP
基本直径
螺纹代号
内螺纹
A
级
大径
中径
小径
中径公差
小径公差
中径公差
0
-0.107
-0.125
0
-0.125
0
-0.142
0
-0.142
0
-0.142
0
-0.180
0
-0.180
0
-0.180
0
-0.180
0
-0.217
0
-0.217
0
-0.217
大径公差
0
-0.214
-0.250
0
-0.250
0
-0.284
0
-0.284
0
-0.284
0
-0.360
0
-0.360
0
-0.360
0
-0.360
0
-0.434
0
-0.434
0
-0.434
外螺纹
B
级
中径公差
0
-0.214
-0.250
0
-0.250
0
-0.284
0
-0.284
0
-0.284
0
-0.360
0
-0.360
0
-0.360
0
-0.360
0
-0.434
0
-0.434
0
-0.434
大径公差
0
-0.214
0-0.250
0
-0.250
0
-0.284
0
-0.284
0
-0.284
0
-0.360
0
-0.360
0
-0.360
0
-0.360
0
-0.434
0
-0.434
0
-0.434
G1/8
″×
28
G1/4
″×
19
G3/8
″×
19
G1/2
″×
14
G5/8
″×
14
G3/4
″×
14
G1
″×
11
G1.1/4
″×
11
G1.1/2
″×
11
G2
″×
11
G2.1/2”X11
G3
”X11
G3.1/2”X11
9.728
13.157
16.662
20.955
22.911
26.441
33.249
41.910
47.803
59.614
75.184
87.884
100.330
9.147
12.301
15.806
19.793
21.749
25.279
31.770
40.431
46.324
58.135
73.705
86.405
98.851
8.566
11.445
14.950
18.631
20.587
24.117
30.291
38.952
44.854
56.656
72.226
84.926
97.372
+0.170
+0.125
+0.125
0
+0.142
0
+0.142
0
+0.142
0
+0.180
0
+0.180
0
+0.180
0
+0.180
0
+0.217
0
+0.217
0
+0.217
0
+0.282
0
+0.445
+0.445
0
+0.541
0
+0.541
0
+0.541
0
+0.640
0
+0.640
0
+0.640
0
+0.640
0
+0.640
0
+0.640
0
+0.640
0
英制锥管螺纹基本
尺寸及公差（牙形角
55
?）
BSPT
基面上的直径
螺纹代号
R1/8
″×
28
R1/4
″×
19
R3/8
″×
19
R1/2
″×
14
R3/4
″×
14
R1
″×
11
R1.1/4
″×
11
R1.1/2
″×
11
R2
″×
11
R2.1/2”X11
R3”X11
大径
9.728
13.157
16.662
20.955
26.441
33.249
41.910
47.803
59.614
75.184
87.884
中径
9.147
12.301
15.806
19.793
25.279
31.770
40.431
46.324
58.135
73.705
86.405
小径
8.566
11.445
14.950
18.631
24.117
30.291
38.952
44.845
56.656
72.226
84.926
基本
4.0
6.0
6.4
8.2
9.5
10.4
12.7
12.7
15.9
17.5
20.6
基准长度
最大
4.9
7.3
7.7
10.0
11.3
12.7
15.0
15.0
18.2
21.0
24.1
最小
3.1
4.7
5.1
6.4
7.7
8.1
10.4
10.4
13.6
14.0
17.1
有效螺纹长度
基本
6.5
9.7
10.1
13.2
14.5
16.8
19.1
19.1
23.4
26.7
29.8
最大
7.4
11.0
11.4
15.0
16.3
19.1
21.4
21.4
25.7
30.2
33.3
最小
5.6
8.4
8.8
11.4
12.7
14.5
16.8
16.8
21.1
23.2
26.3
圆锥内螺纹基面轴向
位移偏
差（
±
mm
）
1.1
1.7
1.7
2.3
2.3
2.9
2.9
2.9
2.9
3.5
3.5