管螺纹的基本尺寸表（3-29）G1/2 、ZG1/2 、（以焊管、镀锌管为例）对应口尺寸代号通称尺寸径1分2分3分4分6分1寸1.2寸1.5寸2寸2.5寸3寸3.5寸4寸5寸6寸8寸10寸1/161/81/43/81/23/411.1/41.1/222.1/233.1/2456外径壁厚每25.4mm最小壁厚类的牙数n28281919141411111111111111111111螺距p0.9070.9071.3371.3371.8141.8142.3092.3092.3092.3092.3092.3092.3092.3092.3092.309基面上的基本直径圆弧半径r牙型高度h大径（基准小径≈中径d2=D2d1=D1直径）d=D0.5810.1257.7237.1426.5610.5810.1259.72.1478.5660.5860.18413.15712.30111.4450.5860.18416.66215.80614.9501.1620.24920.95519.79318.6311.1620.24926.44125.27924.1171.4790.31733.24931.77030.2911.4790.31741.91040.43138.9521.4790.31747.80346.32444.8451.4790.31759.61458.13556.6561.4790.31775.18473.70572.2261.4790.31787.88486.40584.9261.4790.317100.33098.85197.3721.4790.317113.030111.551110.0721.4790.317138.430136.951135.4721.4790.317163.830162.351160.872基准距离446681010131316182122252929有效螺纹长度6.56.59.710.113.214.516.819.119.123.426.729.831.435.840.140.1DN8DN15DN20DN25DN32DN40DN50DN65DN80DN100DN125DN150DN200DN25021.326.933.742.448.360.376.188.9114.3140168.32.82.83.23.53.53.84444.54.52.452.452.83.063.063.3253.58219.11英寸=25.4mm=8分 以上壁厚尺寸以焊管、镀锌管理论重量为例（按GB/T3091-2001标准执行）锥管螺纹的基本尺寸表（3-28）1/2PT 、1/2NPT 、尺寸代号基面上的基本直径每25.4mm大径（基基准距离中径类的牙数n准直径）小径d1=D1d2=D2d=D1/161/81/43/81/23/411.1/41.1/222.1/233.1/242727181814141212121288887.510.24213.61617.05521.22326.56833.22841.98548.05460.09272.69988.608101.316113.9737.1429.412.48715.92619.77225.11731.46140.21846.28758.32570.15986.068.776111.4336.38.73611.35814.79718.32123.66629.69438.45144.52056.55867.61983.526.236108.34.04.1025.7866.0968.1288.61110.16010.66810.66811.07417.32319.45620.85321.438
