1、NPT英制螺纹标准与技术数据 螺纹规格螺距外径C1底径螺纹标号螺牙角度备注NPT1/41.41113.616 1860 NPT3/81.41117.055 1860 NPT1/21.81421.223 1460 NPT5/81.81426.568 1460 NPT12.20833.227 11 1/260 NPT1 1/42.20841.984 11 1/260 NPT1 1/22.20848.053 11 1/260 NPT22.20860.091 11 1/260 NPT2 1/23.17572.699 860 NPT33.17588.608 860 NPT3 1/23.175100.01
2、3 860PT：美国标准的60度锥管螺纹 美制一般密封管螺纹的基本尺寸： 尺寸代号牙数n螺距P牙型高度h基准平面内的基本直径基准距离L1装配余量L3外螺纹小端面内的基本小径大径d=D中径d1=D2小径d1=D1mm圈数mm圈数mmmm1/16270.9410.7527.8947.1426.3894.324.06432.8226.1371/8270.9410.75210.2429.4898.7374.364.10232.8228.4811/4181.4111.12913.61612.48711.3584.105.78534.23310.9963/8181.4111.12917.05515.926
3、14.7974.326.09634.23314.4171/2141.8141.45121.22419.77218.3214.488.12835.44317.8133/4141.8141.45126.56925.11723.6664.758.61835.44323.127111.52.2091.76733.22831.46129.6944.6010.16036.62629.06011/411.52.2091.76741.98540.21838.4514.8310.66836.35037.78811/211.52.2091.76748.05446.28744.5204.8310.66836.350
4、43.853211.52.2091.76760.09258.32556.5585.0111.06536.35055.86721/283.1752.54072.69970.15967.6195.4617.33526.35066.535383.1752.54088.60886.06883.5286.1319.46326.35062.31131/283.1752.540101.31698.77696.2366.5720.86026.35094.932483.1752.540113.973111.433108.8936.7521.43126.350107.554583.1752.540140.9521
5、38.412135.8727.5023.81226.350134.384683.1752.540167.792165.252162.7127.6624.32026.350161.191883.1752.540218.441215.901213.3618.5026.98826.350211.6731083.1752.540272.312269.772267.2329.6830.73426.350265.3111283.1752.540323.032320.492317.95210.8834.54426.350315.79314O.D.83.1752.540354.904352.364349.82
6、412.5039.68826.350347.34516O.D.83.1752.540405.784403.244400.70414.5046.03826.350397.82818O.D.83.1752.540456.565454.025451.48516.0050.80026.350448.31020O.D.83.1752.540507.246504.706502.16617.0053.97526.350498.79224O.D.83.1752.540608.608606.068603.52819.0060.32526.350599.758 注： 可参考表中的最右边一列数据选择攻丝前的麻花钻直径； 螺纹收尾长度（V）为3.47 P； O.D.是英文管子外径（outside diameter）的缩写。标记：美制一般密封管螺纹的完整标记由螺纹特征代号，螺纹尺寸代号和旋向代号组成。左旋螺纹的旋向代号为LH；右旋螺纹的旋向代号省略不标。例如：1/8 NPT-LH,1/8表示螺纹尺寸，NPT为螺纹特征代号，LH表示左旋。美制管螺纹的米制化方法：将管螺纹的原英寸尺寸乘以25.4就转化为毫米尺寸。
