Fasteners are a class of mechanical parts that are used for fastening and are widely used. It is widely used in various industries, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, chemicals, instruments and supplies. It is the most widely used mechanical basic parts.
It is characterized by a wide variety of specifications, different performance uses, and the degree of standardization, serialization, and generalization is also extremely high. Therefore, some types of fasteners with existing national standards are also referred to as standard fasteners, or simply as standard parts.