Oil Line Pipes 1.Standard:BS, GB, DIN, ASTM, API 2.Grade:20#, 16Mn, A53(A,B), St37, St52, ... St42, Q.. 3.Outer Diameter:8-24mm Oil Line Pipes Spiral Seam ... double-side submerged arc welded steel pipe1. Standard: BS, GB, DIN, ASTM, API2. Grade: 20#, 16Mn, A53(A, B ... Wall Thickness 1mm-30mm Grade ASTMA53 Gr. B; API5L Gr. B, X42~X70; ASTMA252 Gr. 2, Gr ...