So pretty reliable then, two pieces of stock from the three I tested made those distinct grey chips you mentioned when drilled, the pickaxe and the odd piece in in the bottom left of the picture are both decidedly cast iron, but that metal ingot next to the pickaxe seems to be a nice piece of steel from the wire-like shavings it gave me, any suggestions on the cast iron? Ive seen something about "heat treating" it to soften it to a forgable piece, that sounds more like tenpering but everywhere ive seen the process they call it heat treating, but that i think was a welding forum (i am not nor do i claim to be a welder!)