Just picked up 10 or more log splitting wedges from my recycling center. I don't go there often, but every so often I find something when I drop off stuff. One of my better finds was an old unicycle, I never got very good at it, but it kept me amused for about a year lol
Btw, I saw your post on your recycle center... bummer.
Another option, construction sites, especially steel framed buildings. I have never been to one that did not have big bolts left lying around and dozens of angle cutoffs. The angle are great for fixtures on mills, bolts always are useful...
Hth
Rich