US Patent 7975717 Pin insert

A valve pin insert has a body for insertion into a valve plate and a stud integrally formed with the body and extending from one end of the body above the valve plate. The body has a lower shank at an end of the body that is opposite from the end at which the stud is positioned, and an upper shank at the end of the body adjacent to the end of the body at which the stud is positioned. The lower shank is of a lesser diameter than the upper shank and an undercut shoulder between the shanks forms a recess opening in the direction toward the lower shank and forms a tooth which shears material of the valve plate as the pin is inserted into a hole in the valve plate.