为了钻削水泵上的铸铁零件的孔,莫斯科“加里宁” 工厂使用了装有硬质合金BK8刀片的钻尖。此种钻尖切 削部分的构造与标准钻尖稍有不同。为了补偿热膨胀和 防止与被加工零件的孔的过分摩擦,在刀片上制有0.1 公厘的倒锥。为了改善排屑情况 在对中心线成15°的钻顶处制有 宽3～4 In order to drill the holes in the cast iron parts of the pump, the “Kalinin” plant in Moscow used a drill bit with a carbide BK8 insert. This drill tip cutting part of the structure and the standard drill bit slightly different. To compensate for thermal expansion and to prevent excessive friction with the hole of the part being machined, an inverted cone of 0.1 mm was made on the blade. In order to improve chip evacuation in the center line into a 15 ° drilling at the top of the system has a width of 3 to 4