The drill bit breaks through the wall and he smiles.

当钻头钻通了墙后，他高兴地笑了。

To deepen a wellbore with the drill bit. To drill ahead.

用钻头加深井眼，往深处钻进。

Are resharpened drill bit inspected and identified prior to use?

再次研磨的钻咀是否在使用前进行检验与确认？

Another probe, this one with a spinning drill bit at the tip, appears.

另外一个探针，顶端有一个纺纱一样的钻头。

Low sprang force, May avoid the milling cutter or the drill bit break.

弹簧力较小，可避免小铣刀或钻头断裂。