Fasteners are usually only a small part of the overall product structure, but they play an important role as an integral part of the product. From the perspective of the application of the world's fastening standard parts, the industry mainly has three major users of the electronics industry, the maintenance and construction industry, and the automobile industry. For example, there are many types of automotive fasteners, which are mainly divided into four categories, including standard fasteners, non-standard fasteners, standard mechanical components and non-standard mechanical components; among them, non-standard fasteners have high quality requirements. Among the non-standard fasteners, engine connecting rod bolts, flywheel bolts, wheel bolts, suspension bolts, etc. are required to have high quality and good stability.
In order to produce high-quality fastening standard products, in the process of selecting the steel used for fasteners, the chemical composition of the steel used must be strictly controlled to reduce the content of harmful elements S, P, O in the steel, reduce oxides, and vulcanize. The inclusions have an effect on the cracking during the production of the fastener; during the heat treatment of the fastener, the temperature, time and atmosphere in the heating furnace are strictly controlled to reduce the oxidation and decarburization of the surface of the fastener.
Therefore, after mass production is completed, final sorting and inspection must be carried out, such as manual selection, vortex sorting, optical sensing size and contour sorting, and sorting out defective products with obvious defects, such as surface cracks and surfaces. Decarburization and unqualified products to meet customer requirements. Non-defective fasteners are the key to ensuring smooth operation of the assembly line, safe driving of the vehicle and a good reputation of the manufacturer.
