Bending aluminum flats

[Xtrykr]

Heya, I have a question about bending 3/4" aluminum flats. Is there a breakpoint or something when I bend/arc these flats? I'm thinking of making a frame for my case from scratch, and was wondering if I have a flat bent at about 30 degrees in both corners whether or not it will lose its strength or something. I went to Home Depot and experimented on some of there flats, and it seemed to bend quite a bit (its very flexible), but I also noticed some "scarring" of the aluminum when I bent it at about 90 degree or more (is the scarring effect bad?).

Anyways, if anyone has any experience or knowledge of bending these flats, please let me know! Thanks a bunch!