square steel tube standards ASTM, DIN, EN, BS, JIS, UL, galvanized, painted rectangular, square certificate:CE, ISO9001 square steel tube, ... rectangular or square, according to standards ASTM A53, ASTM A106, ASTM A795 ... DIN2444, JIS G3444, BS1387, DIN2394, DIN2395, or similar standards. According to buyer's request is available. SIZE: 16mm ...