Casing pipe API SPEC 5CT Application Tubing is used to extracting petruleum and natural gas from a well. Casing serves as walls of a well. Details Size O.D.: 6.0-820.0mm W.T.: 1.0-80.0mm Length: Max.12000mm Grade and Chemical Composition(%) Grade C Si Mn P S Cr Ni Cu Mo V J55(37Mn5) - - - d0.030 d0.030 - - - - - N80(36Mn2V) - - - d0.030 d0.030 - - - - - Mechanical Properties Grade Tensile Strength(Mpa)e Yield Poing(Mpa) J55 379-552 517 N80 552-758 689