标准摘要
[中文适用范围]： 本国际标准规定了自攻螺纹前孔用莫氏锥柄和圆柱柄的亚兰麻花钻的尺寸。 这些钻头设计用于在攻丝公制螺纹（粗牙系列）之前在选定的范围内加工孔： ——M8 至 M30，适用于带有莫氏锥柄的副铣麻花钻； ——M3 至 M14 用于带圆柱形柄的陆地麻花钻。 [外文原描述]： ISO 3438:2013 specifies the dimensions of subland twist drills with Morse taper shanks and cylindrical shanks for holes prior to tapping screw threads. The drills are designed to produce holes prior to tapping metric threads (coarse pitch series) over a selected range of: M8 to M30 for subland twist drills with Morse taper shanks; M3 to M14 for subland twist drills with cylindrical shanks. ISO 3438:2013 complements ISO 2306.
英文名称Subland twist drills for holes prior to tapping screw threads