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″×289.7289.1478.566+0.170+0.28200-0.1070-0.2140-0.2140-0.214G1/4″×1913.15712.30111.445+0.125+0.445-0.125-0.250-0.2500-0.250G3/8″×1916.66215.80614.950+0.1250+0.44500-0.1250-0.2500-0.2500-0.250G1/2″×1420.95519.79318.631+0.1420+0.54100-0.1420-0.2840-0.2840-0.284G5/8″×1422.91121.74920.587+0.1420+0.54100-0.1420-0.2840-0.2840-0.284G3/4″×1426.44125.27924.117+0.1420+0.54100-0.1420-0.2840-0.2840-0.284G1″×1133.24931.77030.291+0.1800+0.64000-0.1800-0.3600-0.3600-0.360G1.1/4″×1141.91040.43138.952+0.1800+0.64000-0.1800-0.3600-0.3600-0.360G1.1/2″×1147.80346.32444.854+0.1800+0.64000-0.1800-0.3600-0.3600-0.360G2″×1159.61458.13556.656+0.1800+0.64000-0.1800-0.3600-0.3600-0.360G2.1/2”X1175.18473.70572.226+0.2170+0.64000-0.2170-0.4340-0.4340-0.434G3”X1187.88486.40584.926+0.2170+0.64000-0.2170-0.4340-0.4340-0.434G3.1/2”X11100.33098.85197.372+0.2170+0.64000-0.2170-0.4340-0.4340-0.434英制锥管螺纹基本尺寸及公差（牙形角55º）BSPT螺纹代号基面上的直径基准长度有效螺纹长度圆锥内螺纹基面轴向位移偏差（±mm）大径中径小径基本最大最小基本最大最小R1/8″×289.7289.1478.5664.04.93.16.57.45.61.1R1/4″×1913.15712.30111.4456.07.34.79.711.08.41.7R3/8″×1916.66215.80614.9506.47.75.110.111.48.81.7R1/2″×1420.95519.79318.6318.210.06.413.215.011.42.3R3/4″×1426.44125.27924.1179.511.37.714.516.312.72.3R1″×1133.24931.77030.29110.412.78.116.819.114.52.9R1.1/4″×1141.91040.43138.95212.715.010.419.121.416.82.9R1.1/2″×1147.80346.32444.84512.715.010.419.121.416.82.9R2″×1159.61458.13556.65615.918.213.623.425.721.12.9R2.1/2”X1175.18473.70572.22617.521.014.026.730.223.23.5R3”X1187.88486.40584.92620.624.117.129.833.326.33.5R3.1/2”X11100.33098.85197.37222.225.718.731.434.927.93.5美制管螺纹基本尺寸及公差（牙形角60º）UN(F)螺纹代号外螺纹内螺纹公差等级公差等级2A2B大径中径小径小径中径大径最大最小最大最小最小最大最小最大JIC螺纹7/16″×20UNF11.07910.87410.25410.1479.5689.72810.03310.28710.42411.1131/2″×20UNF12.66712.46111.84111.73211.15611.32811.60811.87512.01712.79/16″×18UNF14.25214.03113.33513.22112.57312.75113.08113.37113.5214.2883/4″×16UNF19.01218.77317.98117.85417.1217.32317.67818.01918.18419.057/8″×14UNF22.18421.92321.00620.86920.02520.26920.67621.04621.22422.2251-1/16″×12UN26.94426.65525.5725.42524.42524.68925.14625.61325.80126.9881-5/16″×12UN33.29433.00531.9231.77330.77531.03931.49631.96332.15433.3381-5/8″×12UN41.22940.9439.88539.70538.7138.98939.44639.90140.09441.2751-7/8″×12UN47.57947.2946.20546.05345.0645.33945.79646.25146.44947.6252-1/2″×12UN63.45263.16262.07861.9260.93261.21461.67162.12662.33263.5ORFS螺纹9/16″×18UNF14.25214.03113.33513.22112.57312.75113.08113.37113.5214.28811/16″×16UN17.42717.18816.39616.27415.53515.74816.10416.43116.58917.46313/16″×16UN20.59920.36119.56819.44418.70718.92319.27919.60619.76620.6381″×14UNF25.35725.09524.17824.03623.19523.44423.82524.22124.40725.41-3/16″×12UN30.11929.8328.74528.59827.627.86428.32128.78828.97930.1631-7/16″×12UN36.46736.17735.09334.94333.94734.21434.67135.13835.33136.5131-11/16″×12UN42.81742.52741.44341.2940.29740.56441.02141.48841.68642.8632″×12UN50.75450.46549.3849.22548.23548.51448.97149.42649.62750.8SAE螺纹5/8″×18UNF15.83915.61814.92314.80314.16114.35114.68114....
