1" 6061 T52 aluminum channel with 1/8" thick walls. All welded. It's pretty industrial. I think the frame ended up weighing like 12 pounds or something stupid light like that. With everything loaded the computer weighs like 60 I think. I was specific so as to answer the questions I figured people might wonder like "What is that?" A single viewer might only wonder about one item, but I figured it'd be kinda neat.