Hi all,second post on here! Just some backup required on my material choice. I am building a squat rack and Plyometric boxes for my gym at home. For the rack I will be using 75mm square, 3mm thick box section. I have " borrowed " the design from many companies that follow the same principles. Just wondering if there is any rule as to how strong box section is? I am hoping that as long as the welds are good it will hold anything I throw at it! Pics soon! Tim