我厂二金工车间工人李钦恕同志,在大打矿山之仗中,动脑筋,想办法,试验成功了一种精孔钻头,使用效果很好,现介绍如下: 一、精孔钻头的形状: 精孔钻头与标准钻头形状的比较如图1所示。精孔钻头不需要特殊制造,而是用标准钻头改制而成的,图1a是标准钻头,后隙面是磨成圆锥面的,钻尖角为118°,切削刃为直线。图1b是精孔钻头,切削刃部分包 I plant two gold shop workers Liqin Shu comrades in the battle of mines, brains, think of a way, the successful trial of a precision hole drill, the use of good results are as follows: First, the shape of fine hole drill: Fine Hole drill bit and standard drill shape comparison shown in Figure 1. Instead of a special drill, the hole drills are made from a standard bit. Figure 1a shows a standard drill with a flank clearance of 118 ° and a straight cutting edge. Figure 1b is a hole drilled part of the cutting edge package