钢管的公称通径DN和外径φ的对照表 本表中的钢管外径有A、B两个系列，A系列为国际通用系列（俗称英制管）；B系列为国内沿用系列（俗称公制管）。公称通径DN钢管外径1017.2141255\"139.713370028\"711720151/2\"21.3181506\"168.315980032\"813820203/4\"26.9252008\"219.121990036\"914920251\"33.73225010\"273273100040\"101610203242.43830012\"325120048\"121912204048.34535014\"377140056\"14221420502\"60.35740016\"426160064\"16261620652 1/2\"76.17645018\"457480180072\"18291820803\"88.98950020\"508530200080\"203220201004\"114.310860024\"610630 英 制（英寸）1/4\"1 1/4\"1 1/2\"AB公称通径DN 英 制（英寸）钢管外径AB323.9355.36406.4公称通径DN 英 制（英寸）钢管外径AB英制55°圆柱管螺纹的尺寸（国内管道、阀门通用连接螺纹）螺纹代号G 1/8G 1/4G 3/8G 1/2G 5/8G 3/4G 7/8G 1G 1 1/8G 1 1/4G 1 3/8G 1 1/2G 1 3/4G 2G 2 1/4G 2 1/2G 2 3/4G 3G 3 1/4G 3 1/2G 3 3/4G 4G 4 1/2G 5G 5 1/2G 6British Pipe Thread (惠氏管螺纹) -- 圆柱 (BSPP/BSPF)大径螺距每英寸牙数中径小径螺纹牙高内螺纹底公称尺寸孔直径mmmmmmtpimmmmpmmhd=Dd2=D2d1=D1英寸1/8＂9.730.907289.1478.5660.5818.71/4＂13.21.3371912.30111.450.85611.63/8＂16.71.3371915.80614.950.856151/2＂211.8141419.79318.631.162195/8＂22.91.8141421.74920.591.16220.753/4＂26.41.8141425.27924.121.16224.57/8＂30.21.8141429.03927.881.162281＂33.22.3091131.7730.291.47930.51 1/8＂37.92.3091136.41834.941.479351 1/4＂41.92.3091140.43138.951.47939.51 3/8＂44.32.3091142.84441.371.47941.51 1/2＂47.82.3091146.32444.851.479451 3/4＂53.72.3091152.26750.791.479512＂59.62.3091158.13556.661.479572 1/4＂65.72.3091164.23162.751.479632 1/2＂75.22.3091173.70572.231.47972.52 3/4＂81.52.3091180.05578.581.479793＂87.92.3091186.40584.931.47985.53 1/4＂942.3091192.50191.021.479913 1/2＂1002.3091198.35197.371.47997.753 3/4＂1072.30911105.2103.71.4791044＂1132.30911111.55110.11.479110.54 1/2＂1262.30911124.25122.81.4791235＂1382.30911136.95135.51.4791365 1/2＂1512.30911149.65148.21.479148.56＂1642.30911162.35160.91.479161.5英制55°圆锥管螺纹的尺寸（国内管道、阀门通用密封螺纹）螺纹代号R 1/16R 1/8R 1/4R 3/8R 1/2R 3/4R 1R 1 1/4R 1 1/2R 2R 2 1/2R 3R 4R 5R 6公称尺寸 英寸1/16＂1/8＂1/4＂3/8＂1/2＂3/4＂1＂1 1/4＂1 1/2＂2＂2 1/2＂3＂4＂5＂6＂大径mmd=D7.729.7313.216.72126.433.241.947.859.675.287.9113138164螺距mmp0.9070.9071.3371.3371.8141.8142.3092.3092.3092.3092.3092.3092.3092.3092.309每英寸牙数tpi282819191414111111111111111111中径mmd2=D27.1429.14712.30115.80619.79325.27931.7740.43146.32458.13573.70586.405111.55136.95162.35小径mmd1=D16.5618.56611.4514.9518.6324.1230.2938.9544.8556.6672.2384.93110.1135.5160.9螺纹牙高圆弧尺寸内螺纹底mmh0.5810.5810.8560.8561.1621.1621.4791.4791.4791.4791.4791.4791.4791.4791.479mmr0.1250.1250.1840.1840.2490.2490.3170.3170.3170.3170.3170.3170.3170.3170.317孔直径mm6.48.411.214.7518.2523.753038.544.5567185.5110.5136161.5英制普通螺纹 (惠氏螺纹) -- 粗牙 (BSW)公称尺寸大径牙型代号mm英寸d=D1/16＂BSW1.593/32＂BSW2.381/8＂BSW3.185/32＂BSW3.973/16＂BSW4.767/32＂BSW5.561/4＂BSW6.355/16＂BSW7.943/8＂BSW9.537/16＂BSW11.11/2＂BSW12.75/8＂BSW15.93/4＂BSW19.17/8＂BSW22.21＂BSW25.41 1/8＂BSW28.61 1/4＂BSW31.81 3/8＂BSW34.91 1/2＂BSW38.11 5/8＂BSW41.31 3/4＂BSW44.51 7/8＂BSW47.62＂BSW50.82 1/4＂BSW57.22 1/2＂BSW63.52 3/4＂BSW69.93＂BSW76.23 1/4＂BSW82.63 1/2＂BSW88.93 3/4＂BSW95.34＂BSW1024 1/4＂BSW1084 1/2＂BSW1144 3/4＂BSW1215＂BSW1275 1/4＂BSW1335 1/2＂BSW1405 3/4＂BSW1466＂BSW152螺距mmp0.4230.5290.6350.7931.0581.0581.271.4111.5881.8142.1172.3092.542.8223.1753.6293.6294.2334.2335.085.085.6455.6456.356.357.2577.2577.8167.8168.4678.4678.8358.8359.2379.2379.6779.67710.1610.16每英寸牙数tpi60484032242420181614121110987766554 1/24 1/2443 1/23 1/23 1/43 1/4332 7/82 7/82 3/42 3/42 5/82 5/82 1/22 1/2中径mmd2=D21.3152.0412.7683.4594.0844.8785.5377.0348.5099.95111.34514.39717.42420.41923.36826.25329.42832.21535.39138.02441.19944.01247.18753.08659.43665.20571.55677.54883.89989.83296.182102.3108.65114.74121.09127.16133.51139.55145.9小径螺纹牙高内螺纹底孔直径mmmmmmd1=D1h1.050.271.151.7030.3381.92.3620.4062.52.9520.5073.23.4070.6773.74.2010.6774.54.7240.8135.16.1310.9046.57.4921.0177.98.7891.1629.29.991.35510.412.921.47913.415.81.62716.2518.611.80719.2521.342.0332223.932.32424.527.12.32427.2529.512.71130.2532.682.71133.534.773.25335.537.953.25338.540.43.61441.2543.573.61444.549.024.0665055.374.0665660.564.64761.566.914.6476872.545.00573.7578.895.0058084.415.42285.590.765.4229296.645.657981035.657104.2108.65.915110115.25.915116.51216.196122.5127.36.196128.51336.506134.5139.46.506141英制普通螺纹 (惠氏螺纹) -- 细牙 (BSF)公称尺寸英寸3/167/321/49/325/163/87/161/29/165/811/163/413/167/81.001 1/81 1/41 3/81 1/21 5/81 3/422 1/42 1/22 3/433 1/43 1/23 3/444 1/4大径牙型代号mmd=DBSF4.76BSF5.56BSF6.35BSF7.14BSF7.94BSF9.53BSF11.1BSF12.7BSF14.3BSF15.9BSF17.5BSF19.1BSF20.6BSF22.2BSF25.4BSF28.6BSF31.8BSF34.9BSF38.1BSF41.3BSF44.5BSF50.8BSF57.2BSF63.5BSF69.9BSF76.2BSF82.6BSF88.9BSF95.3BSF102BSF108螺距mmp0.7940.9070.9770.9771.1561.271.4111.5881.5881.8141.8142.1172.1172.3092.542.8222.8223.1753.1753.1753.6293.6294.2344.2344.2345.085.085.6455.6455.6456.35每英寸牙数tpi3228262622201816161414121211109988877666554 1/24 1/24 1/24中径mmd2=D24.2554.9755.7256.5187.1998.71210.20911.68413.27214.71216.317.69319.28120.74723.77426.76929.94432.89336.06839.24342.12648.47654.4460.7967.1472.94679.29685.28591.63597.985103.89小径螺纹牙高内螺纹底孔直径mmmmmmhd1=D13.7470.50844.3940.5814.65.10.6255.35.8930.6256.16.4590.7396.87.8990.8138.39.3040.9049.710.671.01711.112.261.01712.713.551.1621415.141.16215.516.341.35516.7517.921.35518.2519.271.47919.7522.151.62722.7524.961.80726.528.141.80728.7530.862.03331.534.042.03334.537.212.0333839.82.32440.546.152.3244751.732.7115358.082.7115964.432.711-69.693.253-76.043.253-81.673.614-88.023.614-94.373.614-99.824.066-1、密封管螺纹（R）配合方式：
英制密封管螺纹有两种配合方式：圆柱内螺纹与圆锥外螺纹组成“柱/锥”配合；圆锥内螺纹与圆锥外螺纹组成“锥/锥”配合.
欧洲国家主要采用“柱/锥”配合螺纹；而欧洲以外国家则主要采用“柱/锥”配合螺纹.两种螺纹的检验量规存在一定不同；目前的ISO英制密封管螺纹量规标准（ISO 7-2：2000）是按“柱/锥”配合体系设计的。.
英制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.英制密封圆柱内螺纹的特征代号为：RP；英制密封圆锥内螺纹的特征代号为：RC；
英制密封圆锥外螺纹的特征代号为：R1（与英制密封圆柱内螺纹配合使用）；R2（与英制密封圆锥内螺纹配合使用）；
左旋螺纹的旋向代号为LH；右旋螺纹的旋向代号省略不标.
对密封管螺纹，利用RP/R1，RC/R2分别表示“柱/锥” 和“锥/锥”螺纹副.
2、非密封管螺纹 标记:
英制非密封管螺纹的完整标记由螺纹特征代号，螺纹尺寸代号，中径公差等级代号和旋向代号组成. 英制非密封圆柱螺纹的特征代号为：G
对英制非密封圆柱内螺纹，其中径公差等级代号省略不标；而英制非密封圆柱外螺纹的中径公尺等
级代号分别为A和B. 左旋螺纹的旋向代号为LH；右旋螺纹的旋向代号省略不标. 当表示英制非密封管螺纹的螺纹副时，仅标注外螺纹的标记代号. 示例：
尺寸代号为2的右旋，非密封圆柱内螺纹：G2 尺寸代号为3的A级，右旋，非密封圆柱外螺纹：G3A 尺寸代号为4的B级，左旋，非密封圆柱外螺纹：G4 B-LH
尺寸代号为2的右旋，非密封圆柱内螺纹与A级圆柱外螺纹组成的螺纹副：G2A
加工内孔螺纹的是管螺纹丝锥， 加工外螺纹用板牙。3、其他：
55°圆锥管螺纹的转化55°圆锥管螺纹，是指螺纹的牙型角为55°、螺纹具有1：16的锥度。该系列螺纹在世界上应用广泛，它的代号，各国规定不同。中国 英国 法国 日本 iso代号 ZG R（外） G PT RR(外螺纹) Rc（内） R R Rc
60°圆锥管螺纹的转化60°圆锥管螺纹是指牙型角为60°、螺纹锥度为1：16的管螺纹，此系列螺纹在我国机床行业和美国、前苏联应用。它的代号，我国过去规定为K，后来规定为Z，现在改为NPT.
