SS400 Carbon Steel Round Bar, compliant with Japan's JIS G3101 standard, is a low-carbon structural steel (C≤0.22%, Mn≤1.40%, Si≤0.35%, P≤0.045%, S≤0.050%). It combines good strength (tensile strength: 400-510 MPa; yield strength: ≥245 MPa for thicknesses <16mm) with excellent plasticity and weldability, making it ideal for construction, bridges, machinery, and automotive components. Widely used in structural frameworks, beams, vehicle chassis, and mechanical parts, it offers reliable performance and cost-effectiveness, though it requires corrosion protection and is unsuitable for extreme high-load applications.