This tool is designed to work with the standard 3/32" male dimple die (or 3/32" substructure die if you have one). Screw this fixture to the workbench leaving it overhang the edge of the bench by about 5/8". The rib will then slip over the fixture and allow alignment of the rivet hole with the center of the die. Using the standard male dimple die, tap the dimple in, and repeat for remainder of dimples. The male die can be held either in the ram of the c-frame and tapped with a hammer, or a .401 rivet gun set with a 3/16" hole in the end. Use caution to avoid a side load on the dies so that the male die pilot does not snap, or the female die does not pop out.