Every week, Team Protocase is bringing you a Proto Tech Tip video, where we’ll give an informative look at a particular aspect of sheet metal fabrication and CNC Machining.

This week, Chris from our Marketing team talks about type 2 and type 3 anodizing for your custom enclosures or parts.

Watch the full video below – or, if you’d prefer to read his Proto Tech Tip, we’ve got the full transcription below the video.

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Hey everybody, Chris here from Protocase with a Proto Tech Tip. Today, we’re going to talk about anodizing.

So here at Protocase, we offer anodizing for your custom aluminum enclosures or parts. Anodizing is an electro-chemical process used to make the surface of non-ferrous metals extremely hard, which makes it less likely to corrode.

At Protocase, we offer two types of sulphuric acid anodizing – and that is Type II and Type III.

So what’s the difference? Both involve an acid bath with electricity, which when used together enhances the oxide layer on aluminum. The key difference between the two is that for Type III Anodizing, the temperature of the sulphuric acid is lowered and the bath runs at a higher voltage.

So to be exact, Type II Anodizing is processed at 19 degrees Celsius, or 66 degrees Fahrenheit, whereas Type III Anodizing is processed at 0 degrees Celcius, or 32 degrees Fahrenheit.

The end result is a denser, wear-resistant layer that creates a harder than smoother finish than Type II. And this is very difficult to show through a screen, but if you have both in your hands together, you can actually really feel the difference.

So if you’re dealing with a project that requires a part or enclosure to be exposed to the elements of heat or electricity, an anodized finish is resistant to corrosion. And because of its hard surface, especially when using Type III, the finish will provide a durable layer that will give the enclosure or part a very long lifespan that’s resistant to scratches and wear.

Anodizing also just gives you a really striking look. There are actually a lot of colors you can choose from. There’s even a vibrant green and violet, which fall under Type II anodizing.

So if you’re sending in your next project into Protocase to manufacture, it’s really important to understand how anodizing will affect the tolerances. Remember, each manufacturing service is different, so if you are using another company for your next project, just be sure to check with them first.

If you’re using a Type II Anodizing Finish, it will add between 0.004” to 0.008”, so less than 0.001”. Type III will add 0.001”.

One other thing to remember when creating your design, is you’re going to want to make sure all of your fasteners in your part or enclosure are aluminum to match the metal that you’ve selected. This will ensure that the fasteners don’t melt or corrode due to the solution being used during the anodizing process.

So feel free to check out our website for more information regarding anodizing, including size restrictions and a complete list of colors that we offer. We put some direct links in the description below.

Be sure also to check out our blog, which outlines many other technical tips. Or, send us an email at info@protocase.com.

Thanks for watching this week’s Proto Tech Tip. I hope this information helps. Be sure to tune in next week for another Proto Tech Tip!

About The Author

Christa Carey

Christa Carey has been with Protocase since the very beginning. In fact, she was the first employee the company hired back in 2002, after working for the Protocase co-founders in a previous job. She graduated in 2000 from Cape Breton University in Nova Scotia, Canada. As the CNC Engineering and Design Services Technical Services Manager, Christa manages a team of engineers and technologists in the CNC Machining Division.

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