smooth surface, good tolerance for Outside Diameter and Thickness. Seamless steel pipe made in cold-drawn and hot-rolling, size such as 1/2", 3 ... ", 15", 16", 18". thickness are sch40, sch80, schSTD, schXS, sch160, and so on.Standard we can do is API 5L, ASTM ... B, X42, X46, X52, X60, X70, X80, P1, P5, P9 and so on. cold drawn and hot rolling seamless steel pipe