Abstract: A die (18) for use in a self-piercing rivet setting apparatus comprises a cavity (25) for receiving therein a protruded workpiece zone consisting of respective portions of the workpieces (2, 3) to be protrudingly deformed toward the die through the pressure of the self-piercing rivet (1). The cavity has a bottom surface provided with a central raised portion (29) protruding from the center of the bottom surface toward a punch. The central raised portion of the cavity has a vertical angle in the range of 90 to 160 degrees. Preferably, the central raised portion has a top formed in a spherical shape. The cavity has an approximately cylindrical outer wall (27) in the periphery thereof. The cavity has a curved inner surface extending from the top of the central raised portion to the lower end (33) of the outer wall through the bottom (35) of the cavity.

Abstract: A die (18) for use in a self-piercing rivet setting apparatus comprises a cavity (25) for receiving therein a protruded workpiece zone consisting of respective portions of the workpieces (2, 3) to be protrudingly deformed toward the die through the pressure of the self-piercing rivet (1). The cavity has a bottom surface provided with a central raised portion (29) protruding from the center of the bottom surface toward a punch. The central raised portion of the cavity has a vertical angle in the range of 90 to 160 degrees. Preferably, the central raised portion has a top formed in a spherical shape. The cavity has an approximately cylindrical outer wall (27) in the periphery thereof. The cavity has a curved inner surface extending from the top of the central raised portion to the lower end (33) of the outer wall through the bottom (35) of the cavity.

Abstract: A self-piercing rivet comprises a flange with a large diameter and a shank with a hollow cavity extending from the flange inward. The rivet is made of aluminum or an aluminum alloy. The shank is a straight cylinder with outer diameter D1, and the hollow cavity in the shank has conical section tapered from the shank end and converging towards the flange at angle &agr; and a straight cylinder section with inner diameter D2 extending from the conical section to the end on the flange side. The shank has a substantially flat ring-shaped end with outer diameter D1 and radial length T1. The angle &agr; of the conical section ranges between 70° and 110°.