| 摘要 |
A self-coining fastener which may be used to join at least two sheets of metal together without leaving a coining mark on one side thereof. The present self-coining fastener therefore produces an entirely flush surface on one side of the joined layers. The fastener comprises a top surface and a bottom surface, the top surface having a larger diameter than the bottom surface. A groove is formed around a perimeter of the fastener in order to transition between the two diameter surfaces. Because the top surface of the fastener has a larger diameter, no coining ring is required in the upper die which installs the fastener. The larger diameter head acts as a self-coining manner to push the metal in the joined layers into the central groove. The result is an installed fastener in which the larger diameter top surface is entirely flush with the top surface of the joined metals, without the presence of a coining mark. |
