管螺纹的基本尺寸表（3-29）G1/2 、ZG1/2 、（以焊管、镀锌管为例）1英寸=25.4mm=8分对应口径尺寸代号每基面上的基本直径最小壁25.4mm牙型高度圆弧半径大径（基螺距p中径小径厚hr≈类的牙数准直径）d2=D2d1=D1nd=D282819191414111111111111111111110.9070.9071.3371.3371.8141.8142.3092.3092.3092.3092.3092.3092.3092.3092.3092.3090.5810.5810.5860.5861.1621.1621.4791.4791.4791.4791.4791.4791.4791.4791.4791.4790.1250.1250.1840.1840.2490.2490.3170.3170.3170.3170.3170.3170.3170.3170.3170.3177.7239.72813.15716.66220.95526.44133.24941.91047.80359.61475.18487.884100.330113.030138.430163.8307.1429.14712.30115.80619.79325.27931.77040.43146.32458.13573.70586.40598.851111.551136.951162.3516.5618.56611.44514.95018.63124.11730.29138.95244.84556.65672.22684.92697.372110.072135.472160.872通称尺寸外径壁厚基准距离446681010131316182122252929有效螺纹长度6.56.59.710.113.214.516.819.119.123.426.729.831.435.840.140.11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DN8DN15DN20DN25DN32DN40DN50DN65DN80DN100DN125DN150DN200DN2501/161/81/43/81/23/411.1/41.1/222.1/233.1/245621.326.933.742.448.360.376.188.9114.3140168.32.82.83.23.53.53.84444..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 、表（3-28）螺纹基本尺寸 (单位:mm)每大径（基25.4mm准直径）类的牙数nd=D2727181814141212121288887.510.24213.61617.05521.22326.56833.22841.988.060.09272.69988.608101.316113.973基面上的基本直径中径d2=D27.1429.412.48715.92619.77225.11731.46140.21846.28758.32570.15986.068.776111.433小径d1=D16.38.73611.35814.79718.32123.66629.69438.45144.52056.55867.61983.526.236108.3基准距离尺寸代号1/161/81/43/81/23/411.1/41.1/222.1/233.1/244.04.1025.7866.0968.1288.61110.16010.66810.66811.07417.32319.45620.85321.438
