Machine screw is a screw that uses a common thread. It can be used for locking nuts and objects with threaded holes. However, the specifications are divided into metric (mm thread), Inch (W Webster thread), and American standards (NC, NF, and Fan). Counting teeth), etc., so there are many specifications. It is recommended to take samples or take the objects with threaded holes to try to lock them directly, which can reduce the purchase error and communication gap.