When looking for an AR-15 or AR-10 you might hear words like parkerized barrel or anodized handguard tosses around without truly understanding what they mean. AR-15 Manufacturers like Bear Creek Arsenal use various coatings to protect the raw aluminum and steel on your firearm from heat, rust, and corrosion so you can be confident in your gun's performance when it matters the most. Learn the most common firearm coatings and see which one will be best for your next build!
Aluminum Coatings (Receivers, Handguards, etc.)
Anodizing is an electrolytic process that thickens aluminum’s naturally occurring oxide layer, resulting in exceptional hardness, abrasion- and corrosion-resistance. When aluminum is exposed to oxygen, it naturally creates a solid layer of oxidation at its surface. Anodizing speeds up this process, providing a layer of protection against the elements. Originally developed to protect airplane parts from saltwater corrosion, anodizing is used extensively on aluminum firearm parts such as AR lower receivers and handguards.
Bear Creek Arsenal anodizes its aluminum parts in-house, by suspending aluminum parts in an acidic bath then applying an electric current between the part to be anodized, which becomes the “anode” or positive electrode, and a “cathode” or negative electrode. The acidic bath causes hydrogen to accumulate at the cathode, and oxygen to accumulate at the anode, which thickens over the aluminum part into a coating of hard aluminum oxide. Anodized aluminum is significantly more resistant to corrosion and wear and is one of the toughest finishes available.
A secondary benefit of anodizing is the creation of “pores” in the metal, which allow anodized aluminum to more easily accept dyes and secondary coatings, such as the traditional black used for most AR components.
One of the newest and most popular finishes firearm finish, Cerakote is a ceramic-based treatment applied as a liquid and then oven-dried. The resulting finish offers extreme resistance to wear, impact, and corrosion and can be applied to metal parts of all types. Arguably just as important as the resistance benefits of Cerakote is the number of colors offered (currently 90), allowing manufacturers to produce firearms in a dizzying array of vibrant hues.
Powder coating is a dry finishing process that has taken the AR-15 world by storm in recent years. The process starts with ingredients that are ground into a powder resembling colored baking flour. In a process called electrostatic spray deposition, a spray gun is used to create an electrostatic charge to the powder particles which are then magnetically attracted to the grounded metal part. After applying, the gun parts are put in a curing oven where the coating chemically reacts with the aluminum to produce long and extremely durable molecular chains. Powder-coated uppers are extremely resistant to corrosion and it is one of the strongest coatings available for your firearm.
At Bear Creek Arsenal, we recently changed from cerakoting to powder coating our colored AR-15 parts because of the increased durability and more vibrant colors. Our rifles and AR-15 uppers are powder coated using an industrial sprayer. The powder-coated parts are then cured in our special oven, and then visually inspected before being sent to the line for assembly.
Bear Creek Arsenal currently offers powder coated rifles and upper assemblies in various colors such as Olive Drab Green, Burnt Bronze, Titanium, Sig Pink, Cosmic Purple, Flat Dark Earth (FDE), and Storm Trooper White.
Steel Finishes (Barrel, BCG, etc.)
Bear Creek Arsenal doesn’t blue any of its firearm components, but the process is worth mentioning as one of the most traditional firearms coatings. Bluing is the coating you will find on many hunting rifles. Bluing is accomplished through an electrochemical process in which the iron in steel is changed to black oxide, forming a blackish-blue film on the outside of the steel. Bluing will not change the dimensions of the metal and can be applied “cold” using store-bought chemicals, or “hot” in a bath of special salts and nitrates. The resulting finish resists corrosion more effectively than bare steel, but not as well as more modern gun finishes and will require continual oiling to protect from rust. While bluing has mostly been replaced by more modern firearms finishes, it is nevertheless a time-honored process.
Also known as Ferric Nitrocarburizing, nitriding is a process of diffusing carbon and nitrogen into the surface of steel, causing it to become as hard as it can be. Nitriding does not change the dimensions of a finished part, rather it forms a two-layer scratch, impact, and corrosion-resistant finish in the metal itself. Black nitride barrels can be identified by their beautiful glossy black appearance and are often a favorite of AR-15 hobbyists.
Parkerizing is a treatment with a long history, dating back to before WWII. Also known as phosphating, parkerizing involves submerging the part into a bath of phosphoric acid with the addition of copper and chlorates which is then heated to around 99 degrees Celsius (or 210 degrees Fahrenheit). The resulting finish is more durable than bluing, and a dark grey or black in appearance.
We hope this guide was helpful for you when trying to pick out your AR-15 rifles, uppers, and lowers, or components. Comment your favorite gun coating and why and check out our other firearm guides for more helpful content!