... 12-508* 1-55mm 3.competitive prices 4.fast delive hydraulic steel tube 1:ASTM A106/A53-B API5L-B 2:OD:20 ... ) Application field:Transportation of oil,gas or fluid,Construction,Electricity,Machine building industy,Chemical industy,Petroleum,Traffic. Standardgradechemical composition(%)CSiMnPSCuNiMoCrDIN 17175ST37ST35 ...