aluminum square tube 1.out dia 20-250mm 2.wall thk ... ,3003,etc. 4. top quality,reasonable price aluminum square tube1.Specifications PRODUCTaluminum tubeALLOY1060,2A12,3003,3A21,5A02,5052, ... 6A02 OUT DIAMETER 20-250mmWALL THICKNESS 3-20mmSHAPE round, square ,oval, flat ect STANDARD GB/T 3880-2006APPLICATION machine ... 87866700.I will reply you soon China manufacturer aluminum square tube for building