I have been wanting to make some of these things for a while. I had a few guys come into the shop and we got to talking, I find out one of them is a "blade smith". After some discussion on material he suggested O1 tool steel. I got busy drawing them up Then over to the machine The first few I cut were aluminum, easier to proof the program and set up in something cheap and easy to machine. Found out the ball groove was a little deep, so I backed it off and cut some steel. And since I went to the trouble to make one, I figured I should at least make 12. I also got a piece of steel from the blade smith that I was able to get 2 out of.