通常都是按样板来刃磨钻头的切削刃,这样有一个缺点,就是不能保证得到对称的钻头,即切削刃a和b不相等(如图1)。用这种钻头来钻孔,不但会扩大孔径和产生不规则的椭圆形,而且还会降低钻头的强度和使用寿命。苏联某厂工具车间工长鲍洛维可夫同志,改进了一种刃磨钻尖用的万能量具(如图2):利用这种量具来刃磨钻头,可以克服以上的缺点。量具的构造如图3。1是量具体;在量具体上用铆钉6固定有侧夹板7和盖板 One of the disadvantages of sharpening the cutting edge of a drill is that it is usually impossible to obtain a symmetrical drill bit. That is, the cutting edges a and b are unequal (Figure 1). Drilling holes with this type of drill not only increases the diameter of the hole and creates an irregular oval shape but also reduces the strength and service life of the drill bit. Comrade Bolaovichov, the chief of the workshop of a factory in the Soviet Union, has improved a universal measuring tool for sharpening drill tips (Figure 2). By using this measuring tool to sharpen drill bits, the above disadvantages can be overcome. Gauge structure is shown in Figure 3.1 is the amount of specific; in the amount of concrete with rivets 6 fixed side plywood 7 and cover