I found a JVC HX-Z30 radio/CD/Casette player in a dumpster.
I was interested in getting the radio part going, but had no luck.
It was nice salvaging the speakers that had some heavy magnets.
I found some screws that I think are copper.
They weren't attracted to a magnet and seemed too heavy to be aluminum.
Never seen any copper screws before.
probably brass - many brass alloys (copper/zinc) are non-ferrous
brass has good hardness and is relatively inexpensive
it is also somewhat resistant to oxidization