Hard Anodizing Line, Custom Type III Hard Coat for Aluminum Components| MEI-AL Technology

This hard anodizing line is engineered for industrial aluminum components requiring a thick, wear-resistant Type III hard coat. Utilizing low-temperature sulfuric acid electrolyte controlled at 0–5°C, the process operates with higher voltage and current density than Type II decorative anodizing.

The system produces film thickness ranging from 20–80 μm, with configurations available for up to 100 μm. Surface hardness typically reaches HV 400–600. Ideal for hydraulic pistons, gears, mold parts, wear-resistant components, military structural parts, and other industrial applications demanding high hardness and wear resistance.

Due to distinct electrolyte and process conditions, this hard anodizing line requires dedicated high-voltage rectifiers, high-capacity low-temperature chillers, and separate process tanks. Hard anodized parts typically exhibit natural black or gray appearance rather than decorative coloring. Production capacity is customized based on part size, racking method, film thickness, and cycle time requirements.

1. Loading and racking
2. Degreasing
3. Rinsing
4. Alkaline etching / neutralization, as required
5. Rinsing
6. Hard anodizing, Type III, low-temperature sulfuric acid
7. Rinsing
8. Sealing
9. Drying
10. Unloading

• Dedicated Type III hard anodizing process with low-temperature sulfuric acid 
• Film thickness 20–80 μm, up to 100 μm in specific configurations
• Surface hardness typically HV 400–600
• High-voltage rectifier and high-capacity chiller matched to hard anodizing load
• Separate process tanks to avoid electrolyte cross-contamination
• PLC control with recipe storage and temperature control
• Manual override for maintenance and special production conditions
• Filtration and exhaust systems for process stability and environmental control
• Suitable for hydraulic, gear, mold and wear-resistant industrial parts
• Sealing options can be selected according to environmental requirements

• Loading / unloading elevator and crane system
• Conductive system and racking
• Process tanks: degreasing, etching / neutralization, hard anodizing, rinsing, sealing
• Tank anti-corrosion linings, stirring system, heating / cooling system
• Dedicated high-voltage rectifier / high-current rectifier
• High-capacity low-temperature chiller
• Micron PP filtration
• Acid fume exhaust and treatment
• PLC control system with recipe storage and temperature control
• Wastewater treatment system
• Separate electrolyte tanks for hard anodizing; not shared with Type II anodizing

A: Type II is a decorative sulfuric acid anodizing process, typically 8–15 μm. Type III is hard anodizing, typically 20–80 μm, with higher hardness and wear resistance.

A: 20–80 μm is typical, with up to 100 μm available in specific configurations.

A: Hard anodizing typically uses low-temperature sulfuric acid at 0–5°C, controlled by a high-capacity chiller.

A: Hard anodized parts are generally not dyed in the same way as decorative anodizing. Natural black or gray appearance is common.

A: No. Hard anodizing requires separate process tanks and cannot share electrolyte with Type II sulfuric acid anodizing.

A: Potassium dichromate sealing or low-temperature sealing can be configured according to environmental requirements.

Get a customized hard anodizing line layout and process solution based on part size, racking method, film thickness, hardness requirements, capacity and factory conditions. Our engineering team can configure the operation mode, tank layout, high-voltage rectifier, low-temperature chiller, filtration, exhaust and wastewater treatment accordingly.