... screws, and without welding.equal angle bar sizes: 1" x 1", 1.25" x 1.25", 1.5" x 1.5"(free accessories: 2pcs corner plates, 6sets M6x12 ... screws)unequal angle bar sizes: 2" x 1.5", 2.25" x 1.5", 2.5" x 1.5 ... "(free accessories: 6sets M8x16 screws) thickness: 1.5mm, 1.7mm, 1.8mm, 2.0mm, 3 ...