... section with competetive price Established in 2009, Zhongtong steel pipes co., ltd is a professional manufacturer for ERW pipes, square tubes, rectangular ... EN10219, EN10210, ASTM A500, GB/T 3094-2000, GB/T6728-2002, GB/T 178-2005, and JIS G 3466 standard. We have strict ... as well as lowest price. Look forward to long-lasting co-operation with you! steel pipes