m2 carbon steel phillips drive black zinc coating precision screw

Industry knowledge：

The differences of screw, nut, bolt, screw and stud are as follows:
The standard saying is that there are no screws and nuts.
Screw is commonly known, with external thread can be called “screw”.
The shape of nut is usually hexagonal, and the inner hole is internal thread, which is used to fit with bolt and tighten related parts.
The head of the bolt is generally hexagonal, and the rod part has external thread.
The screw is small, the head has flat head, cross head and so on, and the rod part has external thread.
Actually, the stud should be called “double head stud”, with external thread at both ends and polished rod in the middle. The long end of the thread is used to connect with the deep hole, and the short end is connected with the nut.