Kmrere42, this is a very complex question and I can not properly answer it. While the Corbin Mfg Company has a very good book on this very subject (Power Swaging), most of it is based upon BnH 5 lead and the CHP-1 press. How long is the lead alloy billet to be and what will be the temperature of the billet to be swaged? I make a lot of lead wire, but it is BnH 7 at the most. I know that for every 1 point increase in hardness, the pressure required to swage an alloy increases far greater. The die body I use has about a 3/16" thick wall, but it's a Corbin die and that's all I know of it's strength. I would assume that a larger bore would require a thicker wall, regardless of the type steel used. If I heat the billet to about 180-220 degrees it swages much easier. The billets are 3/4"d and only 4" long and are well lubricated. That way, there isn't much friction on the die walls, but I would assume that less lubricant and the longer the billet, the more pressure would be required. While I would suggest that a wire making die body of 4140-HT having a 1.5" bore have walls of at least an inch thick for BnH 12 work, is your head stock ( or piston) wide enough ( about 4.5") to accept the die body? I would be interested in other's comments on this subject.