标准摘要
[中文适用范围]： 本国际标准规定了具有保护倒角的中心孔中心钻（Type B）的尺寸。它仅涵盖公制尺寸，未来将被视为这种类型钻头的唯一推荐尺寸。螺旋槽或直槽可由制造商自行选择。除非另有说明，否则这些钻头为右切式。附录A给出了Type B中心孔的推荐尺寸，可通过合理使用本国际标准中列出的中心钻获得。 [外文原描述]： ISO 2540:2016 specifies the dimensions of centre drills for centre holes with protecting chamfer ? Type B. It covers only metric dimensions, regarded as the only recommended dimensions in the future for this type of drills. The flutes can be straight or spiral at the option of manufacturer. Unless otherwise stated, these drills are right-hand cutting. Annex A gives the recommended dimensions for the centre holes, Type B, which can be obtained by a rational use of the centre drills listed in this International Standard.
英文名称Centre drills for centre holes with protecting chamfer — Type B