Shenzhen Alu Rapid Prototype Precision Co., Ltd.
Industry News
Yes, but with important limitations. Die cast aluminum can be anodized, but it is significantly more challenging than anodizing wrought or machined aluminum, and the results are often inconsistent.
Why Die Cast Aluminum is Difficult to Anodize
Die casting uses aluminum alloys with high silicon content (typically A380, ADC12, A360), usually 8–12% silicon. This creates several problems:
Silicon doesn't anodize — It remains as dark spots or smutting on the surface
Porosity — Die castings contain micro-pores from trapped gases, which cause uneven coating
Segregation — Uneven alloy distribution leads to blotchy, inconsistent color
Thin or brittle anodize layer — Hard to achieve uniform thickness
What Results to Expect
Anodize Type | Result on Die Cast |
Clear anodize | Possible, but dull/grayish appearance |
Color anodize | Difficult — colors appear uneven or muddy |
Hard anodize | Very difficult — limited thickness achievable |
Decorative bright | Generally not recommended |
Our Recommendations at Alu Rapid Prototype
When anodizing die cast is acceptable:
Functional/protective coating only (not decorative)
Customer accepts natural gray or dark tone
Tight cosmetic requirements are not needed
Better alternatives we offer:
Alternative Finish | Advantage |
Powder coating | Excellent coverage, hides porosity, wide color range |
Liquid paint | Good aesthetics, flexible color matching |
E-coating | Uniform corrosion protection |
Chrome plating | Decorative, high-end appearance |
Shot blasting + clear coat | Uniform matte texture |
The Best Solution for Anodized Appearance
If your project requires true anodizing with consistent color and finish, we recommend:
Switch to CNC machined aluminum (6061 or 6063 alloy) — anodizes beautifully
Use our rapid prototype vacuum casting for small batches with better surface quality
Specify post-machining of die cast surfaces before anodizing — removes the porous skin layer and improves results significantly
Our Capability
At Shenzhen Alu Rapid Prototype Precision Co., Ltd, we work closely with customers to select the right alloy, process, and surface finish combination from the start — saving time, cost, and avoiding quality issues downstream.
💡 Contact our engineering team early in your design phase. Choosing the right aluminum alloy and finish process together will give you the best result at the lowest cost.
We are happy to review your drawing and recommend the optimal process for your specific application.