China Supplier of Carbon Steel Square Tube for Export

China Supplier of Carbon Steel Square Tube for Export. Wide Size Range: Square tubes from 16x16mm to 250x250mm; Rectangular tubes from 10x20mm to 120x80mm. Diverse Material Grades: Available in Q195, Q235, Q345, ASTM A36, S235, S355, SS400, and more. Hot Dip Galvanized Coating: Zinc coating 40-650g/m2 ensures excellent corrosion resistance and durability. Multiple Surface Options: Offering oil, bare, black paint, and galvanized surface treatments. Flexible Length Customization: Standard 6m available, or customized lengths based on customer request. High Processing Performance: Suitable for cold punching, rolling, bending, drilling, cutting, and welding. Strict Quality Control: Pre-production samples, final inspection, and third-party testing allowed. Comprehensive Certifications: Products certified under ISO9001, CE, EN10210, EN10219, DIN17100, and ASTM standards.