India's Most Diverse Specialized Steel Tube Pipe Company. BestInClass Service Processing. Contact Us. Carbon Pipe Tube . Tubos offer multiple grades of carbon steel covered by ASTM A106, A53 , A333 Grade 6, A671, A672. Alloy Steel Pipe. Tubos are specializes in "chrome moly" which includes SA335 pipe in grades P5, P9, P11, P12, P22 and P23, P91. API 5L Line Pipe ...