Fasteners are very common in life, some need to be fastened mechanically, some require connection and fastening in furniture, etc. The conditions used are not the same as the fasteners and products used. The performance requirements have different requirements.
Usually include the following categories:
1. Bolt: A type of fastener consisting of a head and a threaded rod (cylindrical body with external threads), which is required to cooperate with a nut and is used 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. Stud: A type of fastener without a head that is only threaded at both ends. When connected, one end must be screwed into the part with the internally threaded hole and the other end through the part with the through hole, and then screw on the nut even if the two parts are fastened and connected in one piece. This type of connection is called a stud connection and it is also a detachable connection. It is mainly used for occasions when one of the connected parts has a large thickness, requires a compact structure, or is frequently used for bolting because of frequent disassembly.
3. Screw: It is also a type of fastener composed of two parts of the head and the screw. It can be divided into three categories according to the purpose: machine screws, set screws and special purpose screws. The machine screw is mainly used for a part with a tight threaded hole, and a fastening connection with a part with a through hole, and does not require a nut to fit (this type of connection is called a screw connection and is also a detachable connection; it can also be Fits with a nut for fastening connections between two parts with through holes.) Set screws are used to fix the relative position between two parts. Special-purpose screws such as eyebolts are used for lifting parts.
4. Nuts: With internal threaded holes, the shape is generally flat hexagonal, cylindrical or flat cylindrical, with bolts, studs or machine screws, used to fasten two parts, so that It becomes a whole. The special category of nut, high-strength self-locking nut, is a class of self-locking nuts, with high strength and reliability.