Carbon steel, alloyed steel, Stainless steel seamless tube, straight welding or spiral welding tubes. Description:1) Material: Carbon steel, alloyed steel, Stainless steel seamless tube, straight welding or spiral welding tubes. 2) Standard: API, ANSI, ASME, JIS, DIN 3) As customer requirement 4) Surface treatment: Transparent oil, rust-proof oil, hot galvanizing 5) Price: Very competitive 6) ...