"Screw" is just a generic term for fasteners. It ’s just spoken everyday. It includes: bolts, screws, and nuts. As long as there are threaded fasteners, screws, nuts, bolts, and screws all have one thing in common: they have threads What's the difference besides having a thread?
Bolt: A type of fastener consisting of a head and a screw (a cylinder with external threads), which need to cooperate with a nut to fasten two parts with through holes. This type of connection is called a bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.
2. Studs: There are no heads, only a class of fasteners with external threads at both ends. When connecting, one end must be screwed into the part with the internal threaded hole, the other end is passed through the part with the through hole, and then the nut is screwed on, even if the two parts are firmly connected as a whole. This type of connection is called a stud connection and is also a detachable connection. It is mainly used in the case where one of the connected parts has a large thickness, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly.
3. Screw: It is also a type of fastener consisting of the head and the screw. It can be divided into three categories according to its purpose: machine screws, set screws and special-purpose screws. Machine screws are mainly used for a tight connection between a threaded hole part and a part with a through hole, and do not require a nut. (This connection type is called a screw connection, which is also a detachable connection; it can also be Cooperate with the nut for the fastening connection between two parts with through holes.) Set screws are mainly used to fix the relative position between the two parts. Special-purpose screws such as eyebolts are used for lifting parts.