The torque force section is changed to a regular hexagonal prism from a regular quadrangular prism.

是以由引入段、切削段、锥杆段和扭力段组成的丝锥组成的。

youdao

The torque force section is changed to a regular hexagonal prism from a regular quadrangular prism.

是以由引入段、切削段、锥杆段和扭力段组成的丝锥组成的。

youdao