There are many kinds of automobile fasteners, including bolts, studs, screws, washers, retaining rings, pins, rivets, welding nails and combination parts and connectors. According to the survey, the demand for automotive fasteners accounts for about 23% of the total sales of the whole fastener industry, accounting for the highest proportion of the industry.

From January to October 2021, China's automobile production and sales reached 20.58 million and 20.97 million, respectively, up 5.4% and 6.4% year-on-year. Among them, from January to October, the production and sales of new energy vehicles in China respectively reached 2.566 million and 2.542 million, with a year-on-year growth of 1.8 times.

Japanese auto screw makers say that if you reduce the weight of each screw by 0.5 grams, you can reduce the weight of a car by more than 1 kilogram.

Japanese screw manufactures are vigorously developing a titanium screw. This titanium screw in the face of tension has a strong elastic, TITANIUM screw shaft will be like a spring telescopic, so it is not easy to loose when the strong shaking. It is expected that the titanium screws will be used in pure electric vehicles where safety requirements are particularly high. However, the material cost is dozens of times that of iron and the processing is difficult.

In the connection design of bolts or studs for new energy vehicles, the designer should not only fully consider the size, material, tolerance grade, mechanical properties of bolts, but also fully consider the application environment of bolts, such as temperature (high or low temperature), vibration, cold and hot alternate, corrosion and other environmental factors. Due to the particularity of the environment and the sealing problem between the connectors, exhaust system has been a difficult design problem in the research and development process of automobile manufacturers. Therefore, the research and development of high strength bolts and heat-resistant titanium bolts in hightemperature environment came into being.