We Tianjin Huilitong Steel Tube Co.,Ltd., provide all kind of steel pipes, especially carbon steel pipes(Black pipe). Including Welded pipe ( ERW pipe, SSAW pipe, LSAW pipe) and Seamless Pipe (SMLS Pipe). We can produce round type, square type(HSS Steel), rectangular type and oval type. Almost all the kinds of pipes. So if you have any inquire, please let me know. Our pipes are produced by API 5L, API 5CT, EN 10217, EN 10219 standards. For more information, please visit our website: www.hltsteel.com