What is Type III Anodizing? thumbnail image

What is Type III Anodizing?

Preston Arnet - Oct 7th 2019

If you’ve ever shopped for an AR15, you have surely noticed the level of anodization being flaunted in the guns description. It seems like anodizing is important enough for manufacturers to mention, but they never actually explain what it is. So for those of you who don’t know what anozding is, or why its of grave importance to your firearm; please continue reading.


A Raw 80% Lower fresh from a CNC Machine, before anodization.

By definition anodizing (sometimes referred to as Hardcoat) is an electrochemical process that converts the metal surface into a decorative, durable, corrosion-resistant, anodic oxide finish. In a more comprehensible form, as well as more applicable to our interests; anodizing is the process of taking our aluminum upper, lower, or rail, and dipping it into an acidic bath, where it is then subjected to an electric current, thus making a highly concentrated (and controlled) layer of oxidation on the surface of the aluminum. The anodizing process comes in different grades or ‘types’, withType III being the highest and toughest grade offered in the gun industry.

Now that the technical jargon is out of the way, and we understand what anodizing actually is; lets talk about the benefits of Type III anodizing for your AR15:

Firstly, and perhaps most importantly; Type III anodizing greatly increases strength, durability, and corrosion resistance. These benefits mean that environmental factors like sticks, rocks, dirt, rain, or snow; as well as dropping, dinging, or submerging your rifle will have far less impact on your rifle’s finish. Anodizing, and Type III anodizing specifically, will make your rifle more durable, so you can focus on the hunt, shot, or task ahead; instead of worrying about the well-being of your firearm.

While protecting the aluminum parts on your rifle, Type III anodizing also has benefits for your rifle’s internals. Because the Type III anodization layer is extremely hard, it cuts down on the coefficient of friction; meaning that even before oil is added, it is more ‘slippery’ than other coatings and lesser level anodizations. This reduced friction will allow your gun to cycle more times between servicing, increases the life of the rifles internal moving parts, as well as helps your rifle stay cooler when putting rounds down range at a fast pace.


Type III Hard Anodized Billet AR15 Lower Receiver finished and ready for milling

When taking a look for drawbacks of Type III anodizing, it really is hard to find any negative aspects. Perhaps price could be considered, as reputable companies will occasionally charge a premium price for this premium coating, but it doesn’t break the bank; and is worth every penny. Choosing Type III anodizing is like choosing an insurance policy for your AR15, and after all the time, effort, and money that we like to pour into our beloved AR15 builds; installing Type III anodizing sure seems like a no brainer.