鏜刀是孔加工刀具的一種，一般是圓柄的，也有較大工件使用方刀桿一般見于立車，比較常用的場合就是里孔加工，擴孔，仿形等。但是并不是只能加工里孔，端面外圓也是可以加工的，只是習慣上不是這樣使用。

鏜刀上在鏜桿上 鏜桿固定在鏜床主軸上

鏜孔的時候 零件固定不動 主軸自轉 同時向前伸出

鏜刀的切削部分此時做螺旋運動 將孔鏜至尺寸

Boring tool is a hole processing tool, generally is a round handle, there are larger parts to use the square bar is generally seen in the vertical lathe, the most commonly used occasions is the hole processing, reaming, profile, etc. . However, it is not only possible to process the hole, the end of the outer circle can also be processed, but is not used in this way. The boring cutter is on the Boring Bar, and when the boring bar is fixed on the boring machine spindle, the parts are fixed, the spindle rotates, and the cutting part of the boring cutter is extended forward at the same time to do spiral movement, boring the hole to size