Anodizing is one of the most popular surface finishes for aluminum machined and die-cast parts. It forms a hard, protective oxide layer on the aluminum surface through an electrochemical process. This layer greatly improves corrosion resistance, wear resistance and also delivers consistent decorative colors
1. Type II – Decorative Anodizing (Regular Anodizing)
This is the most widely used option. The oxide film thickness is generally 8–25μm. It supports a wide range of colors, balances appearance and protection, and fits most custom hardware, automation and electronic components.
2. Type III – Hard Anodizing (Hardcoat Anodizing)
Hard anodizing creates a much thicker and denser oxide layer, up to 50μm or more. It offers exceptional abrasion resistance. It is suitable for parts under frequent friction and heavy load, such as sliding structural parts. Hard anodizing has limited color choices, mostly dark tones.
Common Anodizing Color Options：
– Clear / Natural: Retains metallic aluminum texture, ideal if you want the original metal look
– Black: The most common, widely used for industrial and smart device housings
– Red, Blue, Gold, Grey: Popular decorative colors for consumer and precision hardware
Note: Color shade may vary slightly based on aluminum alloy, surface pre-treatment and batch.
Key Points：
– Anodiing only works for aluminum and aluminum alloy; it cannot be applied to stainless steel, zinc alloy or steel.
– The anodized layer adds thickness to part surfaces. You need to reserve tolerance allowance on your drawings.
– Sandblasting before anodizing can create a uniform matte texture. Brushed aluminum before anodizing keeps linear grain patterns.
Anodizing is a reliable, cost-effective finish for aluminum custom parts. Choose decorative anodizing for nice appearance and standard anti-corrosion needs, or hard anodizing when high wear resistance is required.
Tell us your alloy grade, target color and usage environment. Our team will recommend the proper anodizing solution for your CNC or die-cast aluminum parts.