Hi not to hijack the thread , but if unlike Clint who has some material to make the die out of, what are the commercial ones made out of ? Kevin 54 ?
I have been curious of the necessary material for making the die and punch too. Is it suppose to be a hardened steel of some sort?
I'd have to look at one of the catalogs I have to see what the production punches and dies are made from that they sell.
In all of my time in tool & die work, we made the punches and dies out of different materials depending on what the job was and what longevity was needed. Some were made out of cold rolled steel, some out of hot rolled steel, and a lot of them made out of tool steel. Tool steel was nice because it is already tougher than cold rolled steel, already ground to the size that you could order, so it was "vise it up and start cutting".
For the average DIY'er for home use in a garage, I would probably use cold rolled steel, or order some pre heat treat 4140. Some of the 4 way "X" shaped dies we bought we actually aluminum with a hard coat anodize. None of the punched or dies that we ordered in though were heat treated to the point that you couldn't cut them with HSS cutters.
What you want to do though is make sure that you don't work in one area time after time after time. If you do, then you will need to redress your punch and /or die because of indentations. You also want to size your punch and dies according to the material you are using. By that, I mean that you don't want to try and for a 90 degree angle of 1/8" material into a too small of "vee" in the die. In doing that, you'll end up trying to form a 90 where you don't have enough room for the material. And when you try to force it to a 90, what happens is that your corner will be thinner than the rest of the parent material.
And as a side note, for the home person, or even someone in a shop environment, if you have a Press Brake or even your garage 20 ton HF hydraulic press, make sure you always have some aluminum angle, or steel angle iron on hand and make use of it. Add a piece to the front and back of your die to lengthen your surface area out, and your part that you are going to bend will be supported by itself. Over the last few years that I was working, we had to redo hundreds of dies to make them "hands free". The reason being was that people were forming small pieces, and if one is not real familiar with a Press Brake, when the material starts to come up, a lot of people will still hold onto the material. With an automatic Press Brake, once it's in motion, it doesn't back up until it cycles through. One girl at our shop that run a brake for year, got her finger between the punch and die. Not only does it break your finger, it won't cut it, but it explodes instead. So it's just a safe practice to make your tooling to where you don't have to have your fingers close to the punch and die. Plus it's easier to concentrate on one thing instead of trying to hold something straight in the die, then look at a gauge or button, or handle, then back to your piece, and so on.
One more thing about sizing your punch and die to the material is that you don't need to be putting excessive pressure on the material to bend it. A lot of times if you have to double your pressure to get something to form, something else stands a chance of breaking. Anytime that you are using pressure to do something, you want to do it the safest way possible with the least amount of things going wrong.
I watched a coworker one time trying to press out a pin with a long punch. He was using an Enerpac with the button you had to push to bring the ram down automatically. Before I could get over to it to stop him, the punch kicked out when he had maybe 15 tons on it. The punch hit him square in the chest and cut him open. Luckily that was all that happened. So in doing something like that, always use the shortest punch you can. Once you get a pin to break loose in the hole, then you can use something a little longer to finish pushing it through.
) & I have a mate with a machine shop who can mill a couple of grooves in it for beers. 
I will probably still make a heavy duty, narrower die with a large opening that way for use on steel thicker than 1/4".