Anodizing is a complex process whose efficacy depends on several different variables. Material surface in particular can have a major impact on the end result of anodizing. Unlike processes such as painting and powder coating, which can mask a part’s imperfections, anodizing has the tendency to highlight any surface issues that occur during machining. 

In other words, the quality of the machined surface inevitably impacts the outcome of anodizing.

Global Metal Finishing, we’re committed to providing customers with the highest quality anodized aluminum parts. That means meeting fit, form, and function requirements but also ensuring a beautiful cosmetic appearance. 

We work closely with our contract manufacturing partners to set them up for metal finishing that exceeds their expectations—and gives their end customers excellent outcomes. So although we’re sharing general advice in this article, we’re more than happy to have a conversation at any time about optimizing finish quality for your specific parts.

6 Ways to Prepare Machined Parts for Anodizing 

A few steps that can occur during machining to help your metal finisher obtain the best possible finish quality for anodized parts. These steps include:

1.) Remove machining debris.

As much as possible, send your metal finisher parts that are free and clear of any machining debris. Removing metal shavings from deep blind holes and wiping away oils or fluids that remain on your part can go a long way toward improving anodizing results. Get those recesses and features as clean as possible.

2.) Clarify which alloy you used.

Not all metal alloys are created equal. Even differences in material sourcing can impact the anodizing process. Therefore, your metal finisher will want to know as much as possible about the alloy type and temper so that they can determine the best method of treatment.  

3.) Protect surface finish features.

Early finishing processes like tumbling, bead blasting, and vapor honing can affect the cosmetic appearance of a part during anodizing. For example, allowing water from tumbling to air dry on your part can leave water stains behind.

4.) Send your metal finisher dry parts.

A metal finisher will typically clean Parts before anodizing. However, if water or cutting fluids sit on a part after machining and during transit, the part’s surface can become permanently stained or oxidized. Ensuring that parts are completely dry after machining prevents this problem.

5.) Share ideal fixture locations.

When a part is fixtured for anodizing, the fixture’s areas make contact void of anodizing. So, if you design a part with no holes with all features visible during assembly, share where you would prefer the fixture to make contact—and what areas should be avoided. 

6.) Deburr your parts.

If your part has any sharp burrs, there’s a good chance they’ll become dislodged during the anodize process. When this dislodging occurs mid-way through anodizing, the finished part will have a bare spot with no anodize. The best way to avoid this problem is to deburr parts thoroughly before sending them to your metal finisher.

We understand the pressure you’re under to deliver the highest quality parts to your customers—and we’re here to assist you with top-notch metal finishing services. So let’s partner together for the best possible results.