Mainly used for positioning, can also be used to connect, he relies on fixed interference fit pin hole. Generally cylindrical pin is not used for positioning the load, or a load that is very small, less than the number of two, located in the direction of the symmetry of the overall structure of the connecting member is, the better the farther away, the pin is connected to the inner of each a small length of about 1 to 2 times the diameter.