yeah bro im pretty sure they r steel, i welded one of them myself lol. its sh*tty steel tho, i burnt a hole thru one of them and had to get a pro welder to fix my mess up.
also, u forgot to mention that if u want an ultra firm ride, u run some tec-screws thru the steer tube, thru the snapped fork thread and into the fork tube extension. it looks haggard but works well. i only recently stopped running a fork fixed this way, as the steel inner tube was starting to bend (i ride weird, too much stress on bottom of steer tube)