I have been researching dimple dies and speed holes for a while now, and finally made a set, the problem with the commercialy available ones (To me anyways) is that they are on even hole sizes, and I hate hole saws for cutting into plate steel, seems like I never get a hole say to last more thatn 3 or 4 holes, so I made my dies at 1.115 Inches, amd 2.416". You may be asking why? Well the 1.115" hole is what is commonly used for 3/4" conduit, and 2.416 is for 2" conduit, allowing me to use Greenlee "Slug-Splitters" The slug splitters use a 3/8" pilot hole (If you use the correct adapters), and cut through up to 10 Ga stainless steel like butter, especially if you use the Hydraulic Greenlee setup. The Greenlee dies are available from just about every electrical supply house, and while not cheap, work amazingly. I picked up a Hydraulic kit on Ebay for 100.00 with dies from 1/2" to 2" Conduit. Pics: Die: test hole: Size reference: Link to the Greenlee kit I have: http://www.mygreenlee.com/GreenleeD...=showGreenleeProductTemplate&upc_number=34293 My next experiment is going to be drilling and tapping the male die, to see how thick of material I will be able to dimple with the Hydraulic ram form the greenlee kit as it is an 8 ton ram, and much more mobile than my shop press. If it actually works with the ram I will be able to dimple 10 Ga 2x4 box tubing one side at a time, or even open C frame rails.