麻花钻后角大小是保证钻削能否顺利进行的关键,一般是通过手工刃磨两主后刀面来控制。由于麻花钻是一种形状较复杂的刀具,后角的大小又是变化的,手工刃磨一般无法测量,仅凭目测估计,难有一个量化标准,初学刃磨的人往往很难掌握。在实践中,我发现如果借助纸带间接测量,方法简单,效果较好。 Twist angle after the size of the drill is to ensure the smooth progress of the key, usually by hand grinding two main flanks to control. Because twist drill is a more complex shape of the tool, the size of the posterior horn is changing, manual sharpening generally can not measure, just by visual estimation, it is difficult to have a quantitative standard, beginner sharpening people are often difficult to grasp. In practice, I found that if the tape with indirect measurement, the method is simple, the effect is better.