Aluminum Anodizing Surface Finish for Die Casting Components

Aluminum anodization is a metal surface treatment that works by treating the component as an anode electrode in an electrical circuit. The electrolytic passivation process increases the thickness of the natural oxide layer on the component's surface, increasing resistance to corrosion and wear while providing better adhesion for paint primers and glues compared with bare metal.

Contact SKS Die Casting for more information on Anodizing Aluminum Metal Finishing and Surface Finishes, or Request a Quote today.

Why Use an Anodizing Surface Finish for Aluminum Alloy Die Cast Parts?

An anodic surface finish is commonly applied to protect aluminum alloy die cast components. The anodizing metal finishing process changes the surface's microscopic texture and the metal's crystal structure near the surface. Anodized aluminum surfaces are harder than aluminum but have low to moderate wear resistance that can be improved by increasing thickness or applying suitable sealing substances. 

Anodized Aluminum Surface Finish Advantages

Since the electrolytic passivation process works best for nonferrous materials, Aluminum metals are ideal for anodization due to their anodic oxide structure. Some of the direct benefits of anodizing aluminum surface finishes include:

  • Enhanced Durability
  • Improved Corrosion Resistance
  • Color Retention
  • Improved Aesthetics
  • Cost-Saving Advantages
  • Safe & Effective

Black Anodize MIL-A-8625F

MIL-A-8625F Black Anodizing aluminum finishes provide coatings of moderate thickness 1.8 µm to 25 µm (0.00007" to 0.001") and are known as Type II in North America, as named by MIL-A-8625. If close fits are specified in design drawings, our metal finishing processes can provide up to .001” of tolerance.

Additionally, the build-up of anodic coatings, especially Type III, may interfere with assembly. That's why we recommend machining after painting and applying a chem film. Acid etching is a performer in the pre-treatment cleaning of aluminum profiles prior to the anodizing process, which will make any machining finish no better than 63 microinches.

Other Surface Finishing Options

Surface finishing is a secondary service that provides significant benefits to die cast or CNC machined parts. Surface finishes provide your part with an increased cosmetic appeal, protection from corrosion, and surface porosity sealing. SKS also provides the following surface finishing options:

Why Choose SKS for Your Aluminum Anodizing Surface Finishing Needs?

At SKS, we utilize over 100,000 square feet of manufacturing area while employing up to 50 production personnel over two shifts. We use the most technologically advanced die casting and machining equipment and complete in-house design/engineering and tool/die operations. Additional advantages of utilizing SKS include:

  • First-class engineering
  • In-house die cast tool design
  • Injection process parameter development
  • Minimum and maximum wall thicknesses
  • Flow simulation
  • Draft, radii & filets
  • Establishing machining stock
  • Domestic & overseas tooling suppliers

Contact SKS for Aluminum Anodizing Surface Finishes Today

Read more about our aluminum anodizing surface finishes or contact an engineer to start your project today. We can also be reached by phone at 510-523-2541 or email at