For junkyard or found steel what was its old job ie...leaf spring, might b med carbon, railing= mild steel,chisel= tool steel, hammer head= cast steel or D2 etc.
Its guess work but it'll get you in the ball park.
Hope this helps.
I'm in the military and we have to adapt some sheilds to allow for barrels to fit through them.
This steel is HHS; is anyone familiar w/this type of steel ? is it air hardening?
Thanks in advance.