HSS硬质合金1.61.652.52.553.33.44.24.35.05.16.86.98.58.710.310.512.012.214.014.215.515.717.517.721.0……26.5……32.0……37.5……40.5……43.0……螺纹底孔直径螺纹代号钻头直径公制普通粗牙螺纹M48×5.0M30×3.5M36×4.0M42×4.5M45×4.5M16×2.0M18×2.5M20×2.5M24×3.0M8×1.25M10×1.5M12×1.75M14×2.0M3×0.5M4×0.7M5×0.8M6×1.0M2×0.41919.1HSS硬质合金22.0……1.751.7522.5……2.72.723.0……3.53.5527……4.54.5528……6.36.3528.5……77.129……7.37.3533.0……99.134.0……8.88.934.5……9.39.3538……10.510.739……10.810.940……1111.140.5……12.512.741……13.013.142……14.514.743……15.015.143.5……16.516.744.0……1717.145.0……1818.346.0……18.518.746.5……M20×1.5公制细牙螺纹M16×1.0M18×1.5M18×1.0M20×2.0M12×1.0M14×1.5M14×1.0M16×1.5M10×1.25M10×0.75M12×1.5M12×1.25M6×0.75M8×1.0M8×0.75M10×1.0M48×3M48×2M48×1.5M45×3M45×2M45×1.5M48×4M42×3M42×2M42×1.5M45×4M24×2.0M24×1.5M24×1.0M30×3M30×2M30×1.5M20×1.0M36×1.5M42×4M30×1.5M36×3.0M36×2M5×0.5M2×0.25M3×0.35M4×0.5螺纹代号钻头直径（1）普通螺纹攻螺纹前底孔的钻头直径攻螺纹前底孔直径的确定螺纹公称直径（"）1/81/43/81/23/4111/413/811/2每25.4mm内牙数281919141411111111钻头直径（mm）8.811.715.218.924.430.639.241.345.1英制锥螺公称直径每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）1/8288.41/8278.61/41911.21/41811.13/81914.73/81814.51/21418.31/21417.93/41423.63/41423.211129.71111/229.211/41138.311/4111/237.911/21144.111/2111/243.921155.82111/256（2）非螺纹密封的管螺纹攻螺纹前钻底孔的钻头直径英制锥管螺纹（3）英制锥管螺纹和英制锥螺纹攻丝前钻底孔的钻头直径
