Method of making a seal nut

Abstract From the Canadian patent

An improved method of manufacturing a sealing nut having a sealing ring insert is disclosed. The process eliminates the costly step of machining an undercut into the counterbore of the nut blank to provide a means for retaining the sealing ring in place. This is accomplished by leaving a predetermined amount of excess material protruding around the periphery of the counterbore when the counterbore is initially cold formed. When the bearing surface is subsequently flattened by an additional cold forming step the, excess material is forced radially inwardly thereby reducing slightly the diameter of the counterbore at the bearing surface of the nut. The elimination of the undercutting …