Hank,
The alloy we use is a military secret. We buy it from the same mill that did it for the aircraft at the factory before we got involved. All I know is that it is an aircraft grade called P2 and there is not a direct equivalent in our system (I am sure there is something close but I have no idea what it is). If you want more info on metal forming and alloy available on this side of the pond I would check out
www.metalmeet.com. Lots of talent and info there.