各国标准-螺纹基本尺寸对照表
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5/8×18UNF15.83915.61814.92314.80314.16114.35114.68114.95815.1115.8751-1/16×14UN26.94726.68325.74325.60824.7424.96825.37525.78325.96126.987其它美制螺纹9/16×16UN14.25214.01313.22113.10112.3612.57312.92913.25613.41114.2887/8×12UN22.18221.89220.80820.66819.66219.93920.39620.85121.03422.2252-1/4×12UN57.10456.81555.7355.57554.58554.86455.32155.77655.97657.15注：UNC粗牙螺纹系列，UNF细牙螺纹系列， UNEF超细牙螺纹系列， UN不变螺距系列布锥管螺纹基本尺寸及公差(牙形角60º) NPT螺纹代号基面上的直径螺纹长度大径中径小径有效长度管端至基面长Z1/8×2710.2729.5198.76674.572Z1/4×1813.57212.44311.3149.55.080Z3/8×1817.05515.92614.79710.56.096Z1/2×1421.22319.77218.32113.58.028Z3/4×1426.56825.11723.666148.611Z1×11.533.22
