... ST52/35.8 etc 2.Standard: ASTM, DIN, JIS, API 3.Size:1/2"~28 Carbon Steel Pipe A106/A53 ... /API 5 L1. Material: Gr A, Gr B, X42, X52 ... A105,A106,A210,A179,A192,Q195,Q235,Q2152. Standard: API 5L, ASTM A106/A53, ASTM A252,DIN 1629/2391/ ... Details: Quality oil casing tube, the line pipes, the petroleum cracking tube, the fluid pipes, the structure pipes, the boiler ...