1、螺螺纹纹底底孔孔直直径径 公公制制普普通通粗粗牙牙螺螺纹纹 公公制制细细牙牙螺螺纹纹 螺纹代号钻头直径螺纹代号HSS硬质合金M20.41.61.65M20.25M30.52.52.55M30.35M40.73.33.4M40.5M50.84.24.3M50.5M61.05.05.1M60.75M81.256.86.9M81.0M101.58.58.7M80.75M121.7510.310.5M101.0M142.012.012.2M101.25M162.014.014.2M100.75M182.515.515.7M121.5M202.517.517.7M121.25M243.021.0M121
2、.0M303.526.5M141.5M364.032.0M141.0M424.537.5M161.5M454.540.5M161.0M485.043.0M181.5M181.0M202.0M201.5M201.0M242.0M241.5M241.0M303M302M301.5M301.5M363.0M362M361.5M424M423M422M421.5M454M453M452M451.5M484M483M482M481.5攻攻螺螺纹纹前前底底孔孔直直径径的的确确定定(1)普通螺纹攻螺纹前底孔的钻头直径(2)非螺纹密封的管螺纹攻螺纹前钻底孔的钻头直径螺纹公称直径()1/8 1/4 3/8 1/
3、2 3/4每25.4mm内牙数2819191414钻头直径(mm)8.811.715.218.924.4(3)英制锥管螺纹和英制锥螺纹攻丝前钻底孔的钻头直径英制锥管螺纹英制锥螺纹公称直径每25.4mm钻头直径公称直径每25.4mm钻头直径()内牙数(mm)()内牙数(mm)1/8288.4 1/8278.6 1/41911.2 1/41811.1 3/81914.7 3/81814.5 1/21418.3 1/21417.9 3/41423.6 3/41423.21 1129.71 111/229.21 1/41138.31 1/4111/237.91 1/21144.11 1/2111/24
4、3.92 1155.82 111/256钻头直径HSS硬质合金1.751.752.72.73.53.554.54.556.36.3577.17.37.3599.18.88.99.39.3510.510.710.810.91111.112.512.713.013.114.514.715.015.116.516.71717.11818.318.518.71919.122.022.523.027公公制制细细牙牙螺螺纹纹 螺纹代号M20.25M30.35M40.5M50.5M60.75M81.0M80.75M101.0M101.25M100.75M121.5M121.25M121.0M141.5M14
5、1.0M161.5M161.0M181.5M181.0M202.0M201.5M201.0M242.0M241.5M241.0M3032828.52933.034.034.538394040.541424343.544.045.046.046.5M302M301.5M301.5M363.0M362M361.5M424M423M422M421.5M454M453M452M451.5M484M483M482M481.5攻攻螺螺纹纹前前底底孔孔直直径径的的确确定定(1)普通螺纹攻螺纹前底孔的钻头直径1 1 1/41 3/81 1/21111111130.639.241.345.1(2)非螺纹密封的管螺纹攻螺纹前钻底孔的钻头直径(3)英制锥管螺纹和英制锥螺纹攻丝前钻底孔的钻头直径