How many types of parts does the fastener contain?

Fasteners are a general term for a type of mechanical parts that need to be used when two or more parts are tightened and connected into a whole, and they are also called standard parts in the market. Fasteners generally include anchor bolts, studs, screws, nuts, self-tapping screws, wood screws, sealing rings, flat washers, pins, bolts, components and connecting pairs, welding studs and other parts. Today I will briefly explain some of the parts. (1) Anchor bolt: a type of fastener composed of the head and the extruder screw, which must cooperate with the nut to tighten and connect two parts with buried holes. The connection is detachable . (2) Stud: A type of fastener with no head and only two sides with external threads. When connecting, screw one end of it into the part with the internal thread hole, and pass the other end over the part with the buried hole, and tighten the nut so that the two parts are tightened and connected into a whole. This kind of connection is called stud connection, and it is also a detachable connection. One of the parts mainly used for connection is relatively large in thickness, compact in structure or unsuitable for bolt connection due to frequent disassembly and assembly. (3) Nut: Contains internal thread holes, generally flat hexagonal columns, or flat columns or flat cylinders, matched with anchor bolts, screws or steel frame screws, used to tighten and connect two parts, make it a whole. (4) Screw: A type of fastener composed of the head and the extruder screw. According to the field of application, it can be divided into three categories: steel frame screws, set screws and special purpose screws. The installation screw is mainly used for the fast connection between a part with a set screw threaded hole and a part with a buried hole, without nuts. Set screws are mainly used to fix the relative position between two parts, and the special purpose screws are used as lifting parts. (5) Welding studs: half-orc fasteners consisting of main rods and nail heads or no nail heads, which are fixedly connected to parts or components by welding, so as to facilitate connection with other parts. (6) Assemblies and connection pairs: Assemblies refer to a kind of fasteners that make up the supply, such as certain types of equipment screws and flat pads; connection pairs refer to certain types of special anchor bolts, nuts and seals. A type of fastener that is composed of rings, such as high-strength large hexagonal head bolts for steel frame structures.