Keywords: Square Hollow Sections (SHS), Rectangular Hollow Sections (RHS), ‌Cold-Formed Hollow Structural Steel Size: RHS OD: 20mm*10mm ~ 400mm*300mm SHS OD:10mm*10mm ~ 400mm*400mm Standard: ‌EN 10210‌, ‌EN 10219, ‌ASTM A500 Grade B/C‌, ‌ASTM A513 Material: ‌Carbon Steel (e.g., Q235, Q345), Low-Alloy Steel Surface treatment: ‌Hot-Dip Galvanized‌, ‌Painted‌, ‌Powder-Coated