螺纹底孔直径 公制粗牙螺纹螺纹代号钻头直径HSS硬质合金M20.41.61.65M30.52.52.55M40.73.33.4M50.84.24.3M61.05.0 5.1M81.256.86.9M101.58.58.7M121.7510.310.5M142.012.0 12.2M162.014.0 14.2M182.515.515.7M202.517.517.7M243.021.0 M303.526.5M364.032.0 M424.537.5M454.540.5M485.043.0 细牙螺纹 螺纹代号钻头直径铝硬质合金M20.251.751.75M30.352.72.7M40.53.53.55M50.54.54.55M60.756.3 6.35M81.077.1M80.757.37.35M101.099.1M101.258.88.9M100.759.39.35M121.510.510.7M121.2510.810.9M121.01111.1M141.512.5 12.7M141.013.0 13.1M161.514.5 14.7M161.015.0 15.1M181.516.516.7M181.01717.1M202.01818.3M201.518.518.7M201.01919.1M242.022.0 M241.522.5 M241.023.0 M30327M30228M301.528.5M301.529M363.033.0 M36234.0 M361.534.5 M42438M42339M42240M421.540.5M45441M45342M45243M451.543.5