英制管螺纹基本尺寸及公差(牙形角55º)BSPP螺纹代号基本直径内螺纹外螺纹大径中径小径中径公差小径公差A级B级中径公差大径公差中径公差大径公差G1/8″×289
28200-0
1070-0
2140-0
2140-0
214G1/4″×1913
2500-0
250G3/8″×1916
1250+0
44500-0
1250-0
2500-0
2500-0
250G1/2″×1420
1420+0
54100-0
1420-0
2840-0
2840-0
284G5/8″×1422
1420+0
54100-0
1420-0
2840-0
2840-0
284G3/4″×1426
1420+0
54100-0
1420-0
2840-0
2840-0
284G1″×1133
1800+0
64000-0
1800-0
3600-0
3600-0
1/4″×1141
1800+0
64000-0
1800-0
3600-0
3600-0
1/2″×1147
1800+0
64000-0
1800-0
3600-0
3600-0
360G2″×1159
1800+0
64000-0
1800-0
3600-0
3600-0
1/2”X1175
2170+0
64000-0
2170-0