Speedway Motors Sheet Metal Flared Hole Dimple Die, 0.50 Inch Size, Black Oxide Coated Steel Tool for Chassis Panels, Bracing and Fabrication up to 16 Gauge

Used these for the visor I made on my '27 T coupe. Already own most holesaws so didn't want to pay more for self-punching models. I had read other comments/questions about centering the die in the hole, but I had zero issues with this. There's a small lip to hold the toll in place in the hole, and I just hand-tightened them until they were snug until I hit them with my impact. Worked great. Holes were already lubed with 3in1 from the drilling step.

Very easy to use. Made 6 ""dimples"", plus one trial run, on .060"" aluminum - the maximum thickness recommended. I used plenty of oil on both the threads of the tool and the surface of the metal, and it worked flawlessly. I'll buy more of other sizes as needed.