Thinking about building with an AR15 pistol Upper? Set on doing the paperwork and making a short barrel rifle?
Forget the other parts for a second. Let’s talk about the finishes you’ll commonly encounter on uppers. Here are a few you’ll want to know.
Anodized
There’s one basic alloy that all short barrel rifle and AR15 pistol uppers are made from, just like their full-sized counterparts, and it’s aluminum, usually 7075-T6 aluminum.
Uppers are either machined from a billet (called billet uppers) or forged (called forged uppers). In either case, they are commonly treated with a mil-spec hard coat that is an anodized finish.
Anodization is an electrochemical process whereby a thin surface layer of the aluminum receiver is converted into an aluminum oxide.
This finish is very hard, making it wear resistant, and chemically stable, making it resistant to corrosion. Since it is integral with the surface of the receiver, it cannot chip or wear off.
It is also probably the most common finish actually applied to upper receivers themselves.
(To see other AR15 anodized parts in addition to upper receivers, see the previous link.)
Duracoat
Duracoat is a proprietary process that was pioneered by a company in Wisconsin. It is also physical (it’s like a paint) not chemical, so you can apply it at home, easily, unlike anodizing.
Since it is a physical coating, you can also apply it to steel, titanium, and polymer parts, not just aluminum.
Anyway, it’s a two-part painted finish that can be applied to nearly any surface and can result in any color or pattern. It is extremely hard and also insulates the part underneath, which means it offers not only good wear resistance but good corrosion resistance as well.
Other Finishes (for Barrels and Wear Parts)
A complete short barrel rifle upper or AR15 pistol upper is going to come with more than just the stripped upper, as you might know, which means there will be steel parts in addition to aluminum.
As a result, here are some other popular finishes that are commonly applied to the other parts of a complete upper, not just the upper itself.
Phosphate (AKA Parkerized)
A phosphate coated upper or barrel may be referred to as parkerized; this is an older chemical process that uses zinc or manganese along with phosphoric acid to deposit either zinc or manganese phosphate on the affected part.
Phosphate coatings are commonly applied to carbon steel AR15 barrels, but they are also sometimes applied to bolt carrier groups.
Parkerizing produces a smooth, matte finish that is either dark gray or black, and which has extremely high temperature and wear resistance.
Another thing about parkerizing is that it has a bit of a tooth, which enables it to hold onto oil and grease for longer, ensuring a good degree of lubrication on treated wear parts.
Black Nitride
Black nitride is a heated chemical conversion coating that is becoming increasingly popular on AR15 barrels, as well as on wear parts like the bolt carrier group.
It converts the surface of the steel chemically (sort of like how anodized aluminum parts are oxidized) into a “nitride” that has a black, satiny look and which offers excellent wear and corrosion resistance.
Like anodized aluminum, nitride cannot chip or wear off, as it is integral with the steel. As a result, it is very hard and chemically stable.
Moreover, it offers excellent permanent dry lubricity, which means that it’s literally quite slick. As a result, less liquid lubricant can be used with treated parts.
Titanium Nitride
Titanium nitride, also known as TiN, is a finish that is chemically somewhat similar to black nitride, and which offers the same basic virtues.
It is very heat, wear, and corrosion resistant, and since it is integral with the surface of the part, it cannot wear or chip off. Like black nitride, titanium nitride also offers superior permanent dry lubricity.
But the main reason titanium nitride is popular has to be aesthetics - it leaves a very attractive gold-tone finish on treated parts.
Cerakote
Cerakote, which is a ceramic-based coating, is also commonly used to treat AR-15 upper and lower parts.
Basically, it is a commercial finish consisting of a two-part paint that contains a reducer and hardener, which can be applied to steel, aluminum, titanium, polymer, and other substrates.
It leaves a very thin, very uniform coat, and though it does change dimensions slightly, the finish can be as thin as .001”.
Cerakote finishes can be produced in any color or pattern, and offer excellent heat resistance. They also are very hard, and offer excellent wear and corrosion resistance.
To see our full collection of Cerakote AR15 parts, see the previous link.
The Short Barrel Rifle or AR15 Pistol Upper for Your Project Is Here
Ready to start your next home build? Whether you’re here for a short barrel rifle upper, parts, or an AR15 pistol upper, parts or a kit we have what you need. Take a look through our collection and if you have questions about parts, finishes, or compatibility, get in touch with us at Sales@MCSGearup.com.