Standard: Api spec 5ct standard of american petroleum institute Steel grade: J55, k55, n80, l80, n80-1, n80q p110 etc Diamensional tolerances: Types of steel tubes outer diameterwall thickness Cold-rolled tubes tube sizes(mm) tolerances(mm)tolerances(mm) 114.3a0.7912.5 114.30.5½1 Mechanical properties: Standard codesmodels of steel tubestensite strength, mpayield strength, mpa elongation, hardness Api spec 5ct j55517379½552check the table K55517655 N80689552½758 L80(13cr)655552½655n241hb P110862758½965.
