Fasteners are the general term of the class of mechanical parts used in fastening two or more parts (or components) into a whole. It is widely used in energy, electronics, electrical appliances, machinery, chemical, metallurgy, mold, hydraulic and other industries, at the same time, in various kinds of machinery, equipment, vehicles, ships, railway, bridge, construction, structure, tools, instruments, chemical, instruments and supplies, you can see all kinds of fasteners, is the most widely used mechanical foundation parts. It is characterized by a wide variety of variety specifications, different performance uses, and a very high degree of standardization, series, and generalization. Therefore, a class of fasteners that already have national standards is called standard fasteners, or simply standard ones.
