1、普通螺纹钻底孔用钻头直径尺寸（单位 mm）公称直径d螺 距P钻头直径D公称直径d螺 距P钻头直径D粗 0.25 0.75 粗 2.5 15.41 细 0.2 0.8 18 细 21.5115.916.517粗 0.4 1.6 粗 2.5 17.42 细 0.25 1.75 20 细 21.5117.918.519粗 0.5 2.5 粗 2.5 19.43 细 0.35 2.65 22 细 21.5119.920.521粗 0.7 3.3 粗 3 20.94 细 0.5 3.5 24 细 21.5121.922.523粗 0.8 4.2 粗 3 23.95 细 0.5 4.5 27 细 21.5
2、124.925.526粗 1 5 粗 3.5 26.36 细 0.75 5.2 30 细321.5126.927.928.529粗 1.25 6.7 粗 3.5 29.38 细 10.7577.233 细 321.529.930.931.5粗 1.5 8.5 粗 4 31.810 细 1.2510.758.799.236 细 321.532.933.934.5粗 1.75 10.2 粗 4 34.812 细 1.51.25110.510.71139 细 321.535.936.937.5粗 2 11.9 粗 4.5 37.514 细 1.51.2512.512.742 细 4337.838.91 13 21.539.940.5粗 2 13.9 粗 4.5 40.316 细 1.5114.51545 细4321.540.841.942.943.5
