... : 6-20mm 4) Standards: API, GB Packing: Strong bund steel pipeA: Size Range:1) Round pipe diameter: 16mm-610mm, thickness: 0 ... finish: black, blank, bright and galvanized C: Length of each pipe: 500mm-16,000mm D: Steel grade: Q195 - Q235A, ST37 ... SAE1045, X40, X60 etcE: Conforms to international standards, like: ASTM A53, ASTM A500, ASTM A513, BS1387, DIN2391, DIN2394, DIN17175, JIS G3452, EN10210, ...