yes 99% of computer tower cases are steel (aka shred)....watch though, there are enthusiast cases out there that are aluminum (I have one sitting on my desk...my main machine). Make sure to look in the front of the cases with ports...there are typically wires you can pull out and put in the insulated wire bins (I get like $1.25/lb or something for that). If the cases have removable hard drive cages, use a
magnet to make sure they are not aluminum, otherwise they are steel also. Motherboard standoffs are brass alot of time (the little screw things the motherboard attaches to), pull them if you have the time or not (depending on how you value your time)...many screw are stainless as well in a case.
They take up space to transport BUT you can take one side off and fill them up with other little stuff....I tend to leave one door off where my yard can never question if it has
E-waste in it...they don't take that...which is fine for me as I DO! I never care too much as they stack well and I have a 14' trailer with removable steel mesh sides.
Have fun with them!
Bookmarks