Tapping is the process of cutting a thread inside a hole so that a capscrew or bolt may be threaded into it.
攻丝是在一个孔中车出螺纹，以便装上有帽螺钉或螺栓。
2
The intramedullary nail is mainly characterized by including a solid nail body, the upper section of which is an external screwthread rod and a copulate fixedly pressure-adding screwcap;