Product DescriptionStandard: JIS G3445Application: Carbon steel tubes used for machinery, automobile bicycles, furniture, appliance and other machineparts.Steel Grade: STKM 11A/12A/12B/12C/13A/13B/13C/14A/14B/14C/15A/15CChemical Composition:Steel GradeC(%)Si(%)Mn(%)P(%)S(%)Nb/V(%)STKM11A≤0.12≤0.35≤0.60≤0.040≤0.040-STKM12A≤0.20≤0.35≤0.60≤0.040≤0.040-STKM12B≤0.20≤0.35≤0.60≤0.040≤0.040-STKM12C≤0.20≤0.35≤0.60≤0.040≤0.040-STKM13A≤0.25≤0.350.30~0.90≤0.040≤0.040-STKM13B≤0.25≤0.350.30~0.90≤0.040≤0.040-STKM13C≤0.25≤0.350.30~0.90≤0.040≤0.040-STKM14A≤0.30≤0.350.30~1.00≤0.040≤0.040-STKM14B≤0.30≤0.350.30~1.00≤0.040≤0.040-STKM14C≤0.30≤0.350.30~1.00≤0.040≤0.040-STKM15A0.25~0.35≤0.350.30~1.00≤0.040≤0.040-STKM15C0.25~0.35≤0.350.30~1.00≤0.040≤0.040-Mechanical Properties:Steel GradeTensile Strength(N/mm²)Yield Strength(N/mm²)STKM11A≥290-STKM12A≥340≥175STKM12B≥390≥275STKM12C≥470≥355STKM13A≥370≥215STKM13B≥440≥305STKM13C≥510≥380STKM14A≥410≥245STKM14B≥500≥355STKM14C≥550≥410STKM15A≥470≥275STKM15C≥580≥430Delivery Condition:+C(BK)Cold drawn/hard.After the last cold forming,no heat treatment.+LC(BKW)Cold drawn/soft.After the last heat treatment follows the cold drawing there is a light finishing pass.+SR(BKS)Cold drawn and stress relieved annealed. After the final cold drawing process the tubes are stress relieved annealed in a controlled atmosphere.+A(GBK)After the final cold drawing process the tubes are stress relieved annealed in a controlled atmosphere.+N(NBK)Normalized. After the last cold drawing process the tubes are annealed in a controlled atmosphere.Production Process:Packing Condition:Loading Container: