The pin coupling is a pin with an elastic sleeve (rubber material) at one end, which is installed in the flange holes of the two halves of the coupling to realize the connection of the two halves of the coupling. Elastic sleeve pin coupling was once the most widely used coupling in China, and it was formulated as the standard of the Ministry of Machinery as early as the late 1950s. JB08 —60 elastic ring pin coupling was the first standard coupling in China.