smooth surface, good tolerance for Outside Diameter and Thickness. Seamless steel pipe made in cold-drawn and hot-rolling, size such as ... ", 4", 5", 6", 8", 10", 12", 14", 15", 16", 18". thickness are sch40, sch80, schSTD, schXS, sch160, and so on.Standard ... Standard. Steel grade B, X42, X46, X52, X60, X70, X80, P1, P5, P9 and so on. cold drawn and hot rolling seamless steel pipe