Metals 4 U sells custom cut metals, and they throw all their scrap on
a couple shelves near the front of the shop for sale by the pound.
15324 I 35 North
Austin, TX 78728
(512) 879-4575
metals4u.com
Austin Metal and Iron Co. has a section of their yard in the back
corner where you can dig through steel and some aluminum scrap that
they sell by the pound. Can't remember how much it costs, but it's
cheap. I got the sense that this is somewhat of an unofficial policy,
so if you go, try to be extra nice so they continue to make this
resource available to hackers and the like.
1000 East 4th Street, Austin, TX
(512) 477-4640