High quality JIS G3444 Structural Steel Tube

JIS G3444 structural steel pipe is a Japanese standard carbon steel pipe for general structures. Its material properties are divided into 5 levels: STK290, STK400, STK490, STK500, STK540.The chemical composition of the steel pipe is strictly controlled. For example, the carbon content of STK400 is up to 0.25%, and the phosphorus and sulfur contents are up to 0.040%; the carbon content of STK490 is up to 0.18%, the silicon content is up to 0.55%, the manganese content is up to 1.50%, and the phosphorus and sulfur contents are up to 0.040%. In terms of mechanical properties, the minimum tensile strength of STK400 is 400MPa, the minimum yield strength is 245MPa, and the minimum elongation is 23%; the minimum tensile strength of STK490 is 490MPa, the minimum yield strength is 325MPa, and the minimum elongation is 23%.Its manufacturing process is diverse, and it can be produced by seamless, resistance welding, submerged arc welding, forging, etc. The caliber range is 15A-800A, the wall thi…