Aluminum Anodizing (Type II Sulfuric Acid Anodizing)

Core Manufacturing Technologies & Services

LEEDO Technology provides complete aluminum anodizing services, ranging from standard corrosion protection to customized color finishing. By integrating precision aluminum surface engineering, we meet the dual demands of industrial production and product design.

Aluminum Anodizing Solutions
An electrochemical process forms a dense aluminum oxide protective layer on the aluminum alloy surface, effectively improving corrosion resistance and surface hardness.
Custom Color Anodizing
Multiple dyeing options are available to match brand colors or product design requirements while balancing function and appearance.
Corrosion Protection Coatings
The oxide layer is fully integrated with the base material and does not peel easily, providing long-term environmental protection.
Decorative Metal Finishing
Enhances product appearance and texture, making it suitable for consumer electronics, architectural hardware, and other applications where visual quality matters.
Precision Surface Engineering
Strict control of coating thickness uniformity and surface quality ensures that dimensional tolerances of precision parts are not affected.

Main Categories & Technical Specifications

We provide various anodizing processes according to application and specification requirements. The oxide film thickness can be precisely controlled within 5–25μm to ensure that the protective layer depth meets design requirements.

Technical specifications for aluminum anodizing
Standard Anodizing
The most common Type II sulfuric acid anodizing process, providing basic corrosion resistance and hardening effects for most industrial and consumer applications.
Color Anodizing
Dyeing is performed before sealing to create rich colors, making it suitable for product designs requiring specific color schemes.
Clear Anodizing
Maintains the original metallic luster of aluminum while providing protection without changing the surface tone.
Black Anodizing
A dark appearance combined with a protective layer, widely used in consumer electronics, photography equipment, and precision instruments.

Material Compatibility

Applicable to mainstream aluminum alloys, including extruded aluminum and CNC precision-machined parts, with stable and consistent anodizing quality.

Aluminum 5052
Excellent corrosion resistance, commonly used in marine environments, chemical equipment, and building exterior components.
Aluminum 6061
A versatile structural alloy with both mechanical strength and machinability, commonly used in consumer electronics and industrial structural parts.
Aluminum 6063
Excellent extrusion performance and a fine surface after anodizing, widely used in architectural frames, doors, windows, and decorative parts.
Aluminum 7075
A high-strength aerospace-grade alloy suitable for high-stress structural parts, with further surface hardness improvement after anodizing.
Extruded Aluminum
Can be produced flexibly according to cross-sectional shapes and supports continuous surface treatment, making it suitable for batch processing.
CNC Precision-Machined Aluminum Parts
Strict control of oxide layer uniformity ensures dimensional stability for precision tolerance parts.

Surface Finish & Appearance Options

We support multiple color systems and surface textures, from subtle matte finishes and fine sandblasted textures to deep black finishes. Custom dyeing can also be provided according to brand or design requirements, creating metal surfaces that combine functional protection with visual appeal.

Surface finish and appearance options for aluminum anodizing
  • Clear Anodizing
    Preserves the natural metallic luster of aluminum and provides a transparent protective layer, suitable for designs that emphasize the original material appearance.
  • Black Anodizing
    A deep black appearance with a uniform protective layer, widely used in technology-oriented product designs.
  • Silver Anodizing
    Creates a bright silver metallic texture, commonly used for consumer electronics and precision instrument housings.
  • Custom Color Anodizing
    Offers multiple color dyeing options that can accurately match brand color standards and meet customized appearance requirements.
  • Matte Finish
    A low-reflection matte texture that effectively reduces the visual impact of fingerprints and scratches, suitable for handheld devices and equipment panels.
  • Fine Sandblasted Texture
    Sandblasting followed by anodizing creates a uniform fine texture, enhancing both touch and appearance depth.
  • Coating Thickness 5–25μm
    The oxide layer depth can be precisely controlled according to application needs, balancing protection performance and dimensional tolerance requirements.

Design & Manufacturing Considerations

During the early stage of process planning, LEEDO Technology can help evaluate product structure, coating thickness tolerance, color uniformity, and outdoor durability requirements to ensure the anodizing result meets expected quality from the source.

Design and manufacturing considerations for aluminum anodizing
  • Anodizing Thickness Allowance
    Standard anodized films grow both inward and outward from the aluminum surface. Actual dimensional changes vary depending on material, film thickness, and process conditions, so dimensional compensation should be reserved during the design stage.
  • Color Consistency Evaluation
    Deep holes, narrow grooves, and complex curved surfaces may affect dyeing uniformity. Sample validation is recommended during product development.
  • Surface Texture Uniformity
    For batch production, sandblasting, brushing, and pretreatment conditions should be strictly controlled to ensure consistent surface texture and appearance across all parts.
  • Deep Hole & Sharp Edge Coverage Assessment
    Deep holes, blind holes, internal corners, and shielded areas may affect coating thickness uniformity due to current distribution differences. Design for manufacturability (DFM) evaluation is recommended during the design stage.
  • Electrical Contact Area Considerations
    The anodized layer is electrically insulating. If the product requires conductivity, grounding, or EMI performance, masking areas or post-processing methods should be planned in advance during the design stage.
  • Outdoor Durability Requirements
    For outdoor or highly corrosive environments, UV exposure, humidity, heat, salt spray, and chemical media should be considered, with appropriate film thickness and sealing specifications selected according to application needs.

Industrial Applications

We widely serve precision industries and consumer product sectors, providing reliable surface treatment solutions for high-specification manufacturing needs.

Industrial applications for aluminum anodizing

Consumer Electronics / AI Server Components
Precision aluminum parts such as laptop housings, thermal modules, and server chassis that must balance appearance, heat dissipation, and conductivity requirements.
Telecommunications & Networking Equipment
Base station structural parts and optical module housings requiring corrosion resistance and stable electromagnetic compatibility.
Optoelectronics & Display Panel Equipment
Precision frames and support components that require strict coating thickness control to maintain assembly tolerances.
Medical Devices / Aerospace Structural Components
Surface treatment standards that meet medical-grade cleanliness and aerospace specifications, with related certification support available.
Industrial Automation Equipment / Bicycle Components / Motorcycle Components
Suitable for various aluminum alloys requiring wear resistance, corrosion resistance, and lightweight performance.
Architectural Hardware & Decorative Applications
Building components such as door and window frames and exterior wall panels that require long-term weather resistance and aesthetic quality.