I love this disc cutter from Durston. This particular model cuts discs from 3 to 32 millimeters but other models have different ranges. Because of its spring-loaded die plate it's easy to use you can switch the dies in and out without a lot of effort. As you see here I'm just loosening the spring-loaded die plate with the allen wrench that comes with the unit.  Then I'm going to insert the metal between the two plates and tighten it back with the allen wrench. Then I'm going to take the die that I want select the right size and put it in the corresponding hole. Then I just take a hammer give it a good whack or two, open it up and admire your disc.  Unlike some disc cutters, this one cuts non-ferrous materials like brass, copper, and silver so you don't have to have a bunch of disc cutters hanging around. It comes with one jar of Durston lube to prolong the life of the tool and what I like it's the sturdy carrying tray for easy transport and storage.  Find the Durston disc cutter and more great tools at Stuller.com today.