Fasteners are a class of mechanical parts that are used for fastening connections and are widely used. All kinds of fasteners can be seen in all kinds of machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, instruments and supplies. It is characterized by a wide variety of specifications, performance purposes vary, and standardization, serialization, generalization of the species is also very high. Therefore, some people have a national standard of a class of fasteners called standard fasteners, or simply as standard parts. Fasteners are the most widely used mechanical foundation pieces. With China's accession to the WTO in 2001 and entered the ranks of international trade power. China's fasteners a large number of products exported to countries around the world, the world's fastener products are also constantly influx of the Chinese market. Fasteners as one of China's large imports and exports of products, to achieve international standards, to promote China's fastener enterprises to the world, to promote the full participation of fastener enterprises in international cooperation and competition, have a significant practical significance and Strategic significance. Due to the specifications, dimensions, tolerances, weight, performance, surface conditions, marking methods, and acceptance requirements for inspection, marking and packaging of each particular fastener product.