公制螺纹钻底孔用钻头直径尺寸表 M1:粗扣螺距＝Φ 细扣螺距＝Φ M2:粗扣螺距＝Φ 细扣螺距＝Φ M3:粗扣螺距＝Φ 细扣螺距＝Φ M4:粗扣螺距＝Φ 细扣螺距＝Φ M5:粗扣螺距＝Φ 细扣螺距＝Φ M6:粗扣螺距＝Φ 细扣螺距＝Φ M8:粗扣螺距＝Φ 细扣螺距 , ＝Φ7,Φ
M10:粗扣螺距＝Φ 细扣螺距 , , ＝Φ,Φ9,Φ M12:粗扣螺距＝Φ 细扣螺距 , , ＝Φ,Φ,Φ11 M14:粗扣螺距＝Φ 细扣螺距 , , ＝Φ,Φ,Φ13 M16:粗扣螺距＝Φ14 细扣螺距 , ＝Φ,Φ15 M18:粗扣螺距＝Φ 细扣螺距 , ,＝Φ,Φ,Φ17 M20:粗扣螺距＝Φ 细扣螺距 , , ＝Φ,Φ,Φ19 M22:粗扣螺距＝Φ 细扣螺距 , , ＝Φ,Φ,Φ21 M24:粗扣螺距＝Φ 细扣螺距 , , ＝Φ,Φ,Φ23
生产中钻螺纹底孔公式： t＜1mm: Dz=d-t t＞1mm: Dz=d-~t 式中 t 螺距（毫米）
Dz 攻丝前钻头直径（毫米） d 螺纹公称直径（毫米）
公制螺纹钻底孔用钻头直径尺寸表
公称直径d 螺距t 钻头直径 公称直径d 螺距t 公称直径d M1 粗 = M2 粗 = 细 = 细 =
M3 粗 = M4 细 =
M5 粗 = M6 细 =
M8 粗 = M10 细 = 细 = 细 =
M12 粗 = M14 细 = 细 = 细 = M16 粗 = M18 细 = 细 = 细 = 粗 = 细 =
粗 =细 = 粗 = 细 = 细 =
粗 = 细 = 细 = 细 = 粗细细
= = =
M20 粗 = M22 粗 = 细 = 细 = 细 = 细 = 细 = 细 =
M24 粗 = M27 细 = 细 = 细 =
M30 粗 = M33 细 = 细 = 细 = 细 =
M36 粗 = M39 细 = 细 = 细 =
M42 粗 = M45 细 = 细 = 粗 = 细 = 细 = 细 = 粗 = 细 = 细 = 细 = 粗 = 细 = 细 = 细 = 粗 = 细 = 细 =
细 = 细 = 细 = 细 =
M48 粗 = M52 粗 = 细 = 细 = 细 = 细 = 细 = 细 = 细 = 细 =
公制螺纹钻底孔用钻头直径尺寸表
