3xxx series aluminum coils are manganese-based aluminum alloy coils, categorized as anti-rust aluminum. They are among the most widely used anti-corrosion aluminum alloys in modern industry. Featuring an Al-Mn alloy system, mainstream grades include 3003, 3004, 3105 and 3A21. Thanks to excellent corrosion resistance, good formability and moderate strength, they play an irreplaceable role in architectural decoration, packaging, transportation, electronics and many other industries.
Different from low-strength pure aluminum coils, 3xxx series products are reinforced by manganese elements. They retain the superior corrosion resistance and ductility of pure aluminum while achieving improved mechanical properties. With mature production techniques and well-controlled costs, they deliver outstanding overall cost performance, making them the preferred raw material for numerous applications requiring medium and low strength.
Manganese serves as the primary alloying element for 3xxx series aluminum coils. In accordance with the national standard GB/T 3190-2020 Wrought Aluminum and Aluminum Alloys — Chemical Composition, different grades have specified manganese content ranges. Trace amounts of magnesium, copper, iron and silicon are also added to optimize comprehensive performance.
These coils are available in various tempers: O (soft), H12, H14, H16, H18 and H24, each with distinct mechanical properties. O temper offers the best ductility, ideal for deep drawing, bending and other forming processes. H tempers are work-hardened states with higher strength, suitable for structural applications with mechanical performance requirements.
Excellent Corrosion Resistance
Aluminum naturally forms a dense and stable aluminum oxide film (Al₂O₃) on its surface, which prevents further erosion by moisture, acids and alkalis. The addition of manganese further enhances the alloy’s anti-corrosion capability. Its resistance to atmospheric corrosion and stress corrosion outperforms most other aluminum alloys. The coils can serve long-term in humid, coastal and mildly acidic or alkaline industrial environments without rusting. Generally, no extra anti-corrosion treatment is required for most working conditions.
Good Ductility & Formability
3xxx series aluminum coils have remarkable ductility. Especially the O temper grade, it withstands bending, stretching, deep drawing, spinning and other plastic forming processes without cracking, and is perfect for manufacturing workpieces with complex shapes. Work-hardened grades also maintain good ductility for regular bending and rolling, meeting the forming demands of architectural decoration and component production. In addition, it has excellent weldability and can be joined via common processes such as TIG welding and resistance welding, featuring strong processing adaptability.
Moderate and Stable Strength
This series cannot be strengthened by heat treatment, and its strength is adjusted only through work hardening. The tensile strength generally ranges from 100 MPa to 280 MPa. It satisfies the strength requirements of most non-load-bearing structures, while avoiding excessive hardness that would increase processing difficulty. The material boasts stable performance with negligible mechanical property attenuation during long-term service and excellent dimensional stability.
Superior Surface Treatment Performance
With a smooth and uniform surface, 3xxx series aluminum coils are well compatible with anodizing, spraying, baking finish, transfer printing, film coating and other surface finishing technologies. The finished layer features even color and strong adhesion, and is not easy to peel off. It fully meets the appearance requirements of decorative products and is a widely adopted raw material in the building decoration industry.
Eco-friendly and Recyclable
Aluminum alloy is 100% recyclable. After remelting, 3xxx series coils experience minimal performance loss and achieve a high recycling rate, complying with the current trend of green and low-carbon industrial development. No toxic or harmful substances are discharged during production or usage, so the material is applicable to food packaging and other fields with strict environmental standards.
The standard production flow: Aluminum ingot melting → Composition adjustment and refining → Casting → Homogenization treatment → Rough hot rolling → Finish hot rolling → Cold rolling → Annealing / Leveling → Slitting → Packaging. Precise control over chemical composition, rolling and annealing processes ensures stable product performance and high dimensional accuracy.
Available specifications are listed as below:
Thickness: 0.2 mm – 10.0 mm. Custom special thicknesses are available.
Width: 500 mm – 2000 mm, maximum up to 2600 mm. Slitting for narrow coils is supported.
Inner coil diameter: Regular sizes φ405 mm and φ505 mm, customizable on request. Outer diameter of finished coils: φ1200 mm – φ1800 mm.
Coil weight: 1 ton – 3 tons per coil. Extra-heavy coils are available for large-scale continuous production.
Dimensional tolerances comply with GB/T 3880, and also meet ASTM, JIS and other international standards for European and American markets. Two surface quality grades (standard and high precision) are provided to fit diverse application needs.
Architectural Decoration
This is one of the largest application areas. 3003 aluminum coils are widely used for aluminum composite panels, aluminum single sheets, aluminum honeycomb panels, integrated ceiling panels, roof tiles and external wall thermal insulation decorative boards. Featuring good corrosion resistance, easy processing and colorability, they are used for interior and exterior wall decoration of buildings with a service life of over 20 years, far exceeding traditional decorative materials in appearance and durability. 3105 aluminum coils are commonly made into aluminum alloy doors, windows and door frame trims.
Packaging
Non-toxic and highly corrosion-resistant, 3xxx series coils are ideal for food and pharmaceutical packaging. Grades 3003 and 3004 are widely used for beverage can bodies, foil packaging containers, pharmaceutical blister packs and food sealing lids. Lighter than steel packaging with superior barrier properties, they effectively extend the shelf life of contents. They are also applied to chemical product drums and electronic component packaging.
Transportation
The coils are used for interior panels, fuel tanks and skin structures of automobiles and trains, as well as cabin decorative panels and bulkheads of ships. Their light weight and rust resistance fit the lightweight development trend of the transportation industry. 3A21 aluminum coils are widely used for pipelines and pressure vessels, and also have partial applications in the aerospace sector.
Electrical & Electronic Industry
With good thermal and electrical conductivity, 3xxx series coils are processed into heat sinks for electrical appliances, fin materials for air conditioner evaporators and condensers, electronic device housings and soft packaging aluminum foils for batteries. They deliver excellent heat dissipation and stable dimensions for long-term operation of electrical products.
Other Fields
They are also extensively used for outer cladding of thermal insulation pipelines, kitchenware, advertising boards and hardware products. With the development of downstream industries, their application scope keeps expanding.
