... , 20#, ST37, ST44, ST52, ASTM A53, ASTM A106 Rectangular hollow section:1.Item: square pipe2.Standard: GB, ASTM, BS, JIS, 3 ... the order signedWe are specialized in the supply of ERW pipe, seamless steel pipe, hollow section, galvanized steel coins, steel plate, stc. ... We supply steel as the manufacturer's price to ...