I need to make a hot cut chisel for making animal heads. I had heard that S-1 was the steel of choice since it could be made very thin and still have excellent heat resistance. I do not have any S-1, however I do have access to the following steels: A36, 5160, O-1, and automotive/truck engine valves. Which one of these would be my best choice? Thanks, Dan Crowther http://www.oakandacorn.com