We have a local scrap yard that allows you to drive through and pick up anything you want. Your vehicle is weighed before you go in and on the way out. I was there once just after a machine shop dumped a load of scraps. Hundreds of pieces of short shaft from 3/4" to 6" diameter x 4" to 18" long. Lots and lots of small sheet stock up to 2" thick. Lots of structural steel also. I was in heaven and threw quite a few pieces in my van. I guessed that I had maybe 150 lbs, but I actually had loaded 410 lbs! At .25 cents a pound, it wasn't to bad an investment for enough metal to last me for years. No idea of the type of metal, but it'll work for me. The yard also separates electric motors from equipment that comes in, but unfortunately, they remove them using a track-hoe bucket. All their cast iron (machines) is kept in one area, but I've never seen one that wasn't damaged badly from the unloading process. Still, I've gotten a few hand-wheels and such from them.
Jack