Finally able/must use them and the burrs just fell off the taper. Hardly anything touches low alloy stainless steel (308). I haven't tried the others on this stuff since the first one just blew up. I tried another burr on a medium carbon steel and it seemed to work, but I bought this one because the description lists STAINLESS STEEL PART as one of the metals it can work with. You will not. Waste of $50!