I believe what I have are steel, there was rust on them when I got them..
Most are steel, yes. Fun fact: Most of them were manufactured by companies that make nails. Go figger, huh? I don't know if it's still true, but back the day the guys flying the helos referred to the rocket rounds with flechette warheads as "nails". "Coming around for another pass..gonna put some nails in to the tree line.."