margin of drill

用法例句

On the basis of experiment results from rock fragmentation by slantly penetrated cutting toolsthe drilling process of large cutting element drill bits is analysed and the penetration rate formulae for large cutting element drill bits in the case of rotary drilling is also derived.

根据刃具斜切入破岩的一些试验研究成果，分析了大切削具钻头的钻进过程，推导出了大切削具钻头进行回转钻进的机械钻速公式。