Hello Everyone.



I found a mystery metal plate. 5/8 thick 18"x36" with a hole in it. At first I hit it with a magnet and it didn't feel like it was sticking so I thought, awesome big piece of Ali. Nope. Went to pick it up and it was super heavy. It weighs about 120#. I took it back to the garage and tried the magnet again and it barely sticks. It kinda looks like galvinized. It looks like it was cut with a plasma cutter. I scratched it and it's shiny. I can't figure it out.

Thank you in advance for your help.