1, What is fastener?

Fasteners are a general term for a class of mechanical parts used when two or more parts (or components) are tightly connected into a whole. Also known as standard parts in the market.

2, it usually includes the following 12 types of parts:

Bolts, studs, screws, nuts, tapping screws, wood screws, gaskets, retainers, pins, rivets, assemblies and connection pairs, welding nails.

(1) Bolt: A type of fastener composed of two parts of the head and the screw (a cylinder with external threads), which needs to be matched with the nut for fastening and connecting two parts with a through hole. This type of connection is called bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.

As shown below: (2) stud: no head, only a class of fasteners with external threads at both ends. When connected, one end of it must be screwed into the part with an internal threaded hole, the other end through the part with a through hole, and then screw on the nut, even if the two parts are tightly connected into a whole. This connection form is called a stud connection, which is also a detachable connection. It is mainly used for occasions where one of the connected parts is thick, requires compact structure, or is not suitable for bolted connection due to frequent disassembly. (3) Screw: It is also a kind of fastener composed of two parts of the head and screw, which can be divided into three categories according to the use: steel structure screws, setting screws and special purpose screws. Machine screws are mainly used for the fastening connection between a part with a tight threaded hole and a part with a through hole, without the need for nuts (this connection form is called screw connection, and it is also a removable connection; It can also be used in conjunction with nuts for fastening connections between two parts with through holes.) The setting screw is mainly used to fix the relative position between two parts. Special purpose screws such as ring screws for lifting parts.