In life, copper bolts, copper screws, copper screws, etc. are often mentioned. What is the difference between them? In fact, the standard saying is that there are no copper screws and copper nuts. Copper screws are commonly known, and those with external threads can be called "screws". The shape of the copper nut is usually hexagonal, and the inner hole is an internal thread, which is used to cooperate with the bolt and tighten the related parts. The nut is commonly called, and the standard should be called "nut". The head of the bolt is generally hexagonal, and the shank has an external thread. Copper screws are small, with flat heads, cross heads, etc. on the head, and external threads on the rod. Copper studs should actually be called "double-ended studs", with external threads on both ends and a polished rod in the middle. The long end of the copper thread is used to connect with the deep hole, and the short one is connected with the copper nut.

　　Standard fasteners are divided into twelve categories, and the selection is determined according to the use occasion of the fastener and its use function.

　　1, copper bolt

　　Copper bolts are widely used in detachable connections in mechanical manufacturing, and are generally used in conjunction with nuts (usually plus a washer or two washers).

　　2, copper screw

　　Copper screws are usually used alone (sometimes with washers), usually for fastening or tightening, and should be screwed into the internal thread of the body.

　　2, copper stud

　　Copper studs are mostly used to connect one of the connected parts with a large thickness, and need to be used where the structure is compact or the bolt connection is not suitable due to frequent disassembly. Studs are generally threaded at both ends (single-end studs are threaded at one end). Usually one thread is firmly screwed into the body of the component, and the other end is matched with a nut to play the role of connection and fastening. To a large extent, it also has a fixed distance function.