拉刀刃磨后,用一块20×50×500毫米的木板“背”一下刀的后面,再蹭刀部,就能有效地提高拉削质量和拉刀耐用度。这是为什么呢?原来拉刀刃磨后,刀刃虽然锋利,但是会留有肉眼不易察觉的细微磨痕和锯齿形缺口和毛刺断口。这些缺陷在工作过程中会逐渐加重,影响拉刀的拉削质量和使用寿命,所以人们经常要“背”刀。“背”刀好坏直接影响拉刀的使用效果。我们用木板“背”拉刀,经过几年使用证明效果很好,是一种费劲不大,收效显著的背刀方法。 Broach sharpening, with a piece of 20 × 50 × 500 mm wood “back” about the back of the knife, and then rub the blade, you can effectively improve the quality of broaching and broaching durability. This is why? The original broaching knife sharpening, although the sharp edge, but will leave the naked eye is not easy to detect subtle wear marks and serrated gap and glitch fracture. These defects in the work process will gradually increase, affecting broaching broaching quality and service life, so people often want to “back” knife. “Back” knife a direct impact on the use of broach effect. We use the wood “back” broach, after several years of use proved to be very good, is a strenuous, significant effect of the knife method.