深孔加工在机器制造厂里被认为是一件困难的任务。早期采用的刀具是双刃钻头,排屑方式为外排屑,切削效率很低,加工质量亦差。后来创造了单刃钻头,通常被称为枪孔钻。它有一个硬质合金刃头和两个导向垫,其中一个处在刀刃的相反位置上,另一个在刀刃下面的90°位置上,材料为碳化钨,排屑方式为外排屑。这种刀具最主要的缺点是弯月形的钻杆截面刚性 Deep hole machining is considered a difficult task in machine builders. Early use of the tool is a double-edged drill, chip removal for chip removal, cutting efficiency is very low, processing quality is poor. Later created a single-edged drill, commonly known as gun hole drill. It has a carbide tip and two guide pads, one on the opposite side of the blade and the other on the 90 ° position below the blade, which is made of tungsten carbide and has the chip evacuation method. The main disadvantage of this tool is the cross-section rigidity of the meniscus