中心钻是一种使用很广而且消耗量比较大的刃具,由于切削刃部尺寸很小,所以要求比较高的同心度。为了使中心钻的圆柱部分和圆锥部分同时获得一定的后角,它要求斜向铲背,铲磨的方向同它的中心线成12°左右的夹角,铲背量一般都很小。因此在没有专用设备的情况下,生产中心钻是比较困难的。为了及时供应本厂生产上的需要,我们曾利用废旧的机床零件改装成一套简易的卡具,使用结果却 Center drill is a widely used and relatively expensive tool, due to the small size of the cutting edge, so require a high degree of concentricity. In order to obtain a certain clearance between the cylindrical part and the conical part of the center drill, it requires a sloping back of the shovel with an angle of about 12 ° to its centerline. The shovel back amount is generally small. Therefore, in the absence of special equipment, production center drilling is more difficult. In order to timely supply our factory production needs, we have used the waste of machine parts converted into a simple set of tools, the result is