The fastener is a kind of mechanical part which is used for fastening connection. In all kinds of machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, instruments and supplies, and so on, can see a wide range of fasteners. It is characterized by a wide range of varieties and specifications, the use of different performance, and standardization, serialization, generalization of the species is also very high. Therefore, some people have the national standard of a fastener known as standard fasteners, or referred to as standard parts. Fasteners are the most widely used mechanical components. With China's accession to the WTO in 2001 and entered the ranks of international trade. Fastener products in our country have been exported to many countries and all over the world. Fasteners as China's import and export of a large amount of products with international standards, to promote China fastener enterprises to the world, to promote the fastener enterprises to fully participate in international cooperation and competition, all has the important practical significance and strategic significance. Due to the specific specifications, dimensions, tolerances, weight, performance, surface conditions, marking methods, and acceptance inspection, marking and packaging of each specific fastener product.