Patent ID: 7937821

Claim:
A method of joining workpieces having a hole, the method comprising: (a) using a blind rivet having a hollow central body segment, a preformed tool-side flange and a blind-side end; (b) inserting the rivet body segment into the hole and the tool-side flange into a frusto-conical depression of a tool-side surface of the workpieces; (c) applying an axial setting force to the rivet body by use of a mandrel head and a shoulder, the shoulder having a graduated cross-sectional diameter between a mandrel shaft and the head, the shaft operably extending through the rivet body segment; (d) laterally expanding the blind-side end of the rivet into a frusto-conical depression in a blind-side surface of the workpieces, all of the blind-side and tool-side ends of the rivet being substantially flush with or below the adjacent outer workpiece surfaces after setting; (e) the workpiece hole being radially larger than the central body segment of the rivet prior to setting, and radially expanding the central body segment of the rivet to fill the workpiece hole during setting; and (f) removing the mandrel head, shoulder and shaft from the blind rivet.