dancom - I am ashamed to say that I don't know exactly what type of steel it is made of since I forged it from an old ball peen hammer. Needless to say though it's quite hard, after it was quenched we tested it in a hardness tester and it came out at 63Rc prior to tempering.
Ah, sorry man. My first read was more like forged with a ball peen, instead of from a ball peen. Cooler yet!