The screw connection is widely used in urban rail and subway vehicles. According to the problem of fastener failure which affects the safe operation of vehicles, the fastener performance is put forward higher requirements, and the research prospect of fastener development is forecasted.

Screws and nuts are essential parts of mechanical transmission. Threaded fasteners are used for connection, positioning and sealing. They are the most commonly used detachable connections, in which bolts are used the most.

With the large capacity and upsizing of various types of urban rail subway vehicles, as well as the continuous improvement of power and speed, the working conditions of vehicle fasteners have become more severe. Throughout all kinds of driving failure cases, the failure of fasteners is a huge hidden danger affecting the safe operation of urban rail subway vehicles. Therefore, higher requirements are put forward for the performance of fasteners.