• Outer Diameter：8mm~140mm
• Thickness：0.8mm~20mm
• Length：6meters, 9meters, 12meters, Random Length
• Surface：Annealing Bright, Phosphating
• Tolerance of Size：+,- 0.05mm
• Transport Package：Bundled, Wrapped, Wooden Cased.
• Specification：DIN2391
• Trademark：Iron&steel
• Origin：China
• HS Code：73041990
• Production Capacity：100 Tons Per Month

DesignationSymbolDescriptionCold finished (hard)BKTubes do not undergo heat treatment following the final cold forming and,thus, have a rather high resistance to deformationCold finished (soft)BKWThe final heat treatment is followed by cold drawing involving limited deformation.Appropriate further processing allows a certain degree of cold forming(e.g. bending expanding).Cold finished and stress-rellevedBKSHeat treatment is applled following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degreeAnnealedGBKThe last cold forming process is followed by annealing in a controlled atmosphereNormalizedNBKThe last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphereMaterialChemical composition (%)CMnPSSiNiCu20#
AISI 10200.17~0.230.35~0.65≤0.035≤0.0350.17~0.37≤0.3≤0.2545#
ASTM1045, DIN450.42~0.50.5~0.8≤0.04≤0.0450.17~0.37≤0.25≤0.25Mechanical Properties of seamless steel pipeSteel materialTensile Strength MpaYield strength MpaElongation
%HardnessStraightness20#≥510≥245≥25≤156HB0.3~1.045#≥647≥355≥16≤HRC620.3~1.0