Standard: GB, ASTM, API Outer Diameter: 18 - 460 mm Thickness: 3 - 60 mm Product NameASTM STANDARD Carbon Steel PipeBrandZHONGYE Steel Pipe ( By ourself ) ... of 3~30mmStandardGB/T8162,GB/T8163 and DIN/JIS/ASTM standarda. DIN Standard 10#(ST37-2,ST35-8),20#(ST42,ST45-4 ... -C,A210-A-1,A315-B,AISI1020),45#(AISI1045), 16mn(ASTM A210-C) etc.Usageboiler use,water transport, building, machinery, ...