If the disks are tempered, you'll have a helluva time cutting them out and shaping them, without taking the temper back out. Even if you use a plasma cutter, the temper will be gone on the edges. Fortunately, Tempering something that small is pretty simple. Cut out the heads by whatever method you choose, and if you do it with a saw, I would advise heating the area first to get rid of the temper. Anything ove 750oF will do. you can tell it's hot enough by sanding to bare metal before you heat, then heat from the opposite side, so you can watch the colors. When the steel turns blue, then clear/greenish, the temper is burned out of it. if you cut with a torch, the problem is already solved for you. Shape the individual blades, all the way to the finished edge. All you need for 1" broadheads is a porpane, or better yet, MAPP torch. a forge is not required, and Oxy/Acetylene is overkill, but will work if you keep it way low. Get a can of oil, nearly any sort will do, and keep a lid handy to snuff it if neccessary. Dim the lights, and heat each point to cherry red, quickly, then drop it in the oil. Clean off the oil, then bake them in your oven at 450oF for 2 hours. Things like disk blades tend to be medium carbon steel alloys, with other additives to make them tough and abrasion resistant, so that temperature will do a good job tempering. If you use something with a higher carbon content, you need to heat it to a higher temperature, or it may be too brittle. When I've done knife blades from certain brands of files, I needed to use a torch, and watch for the colors again, because the kitchen oven doesn't get hot enough, but it should be fine for the material you're using. When you finish, they will have a natural black oxide coating, that you can choose to polish, or not, and all you need to do is resharpen. Also, a bevel grind, on one side of the edge only, will be way sharper and easier to maintain. Pick the side that's easiest for you to grind, depending on if you're right or left handed.
