In the early days of mass firearm production muskets, pistols and early rifles had two popular and distinctive coatings used to protect the metal components from external destructive factors (mainly rust). Those two coatings were browning and bluing. The names say it all; one method left the metal looking brown while the other left a dark deep blue coating. Browning and bluing look great and work well for what they are although both can take days to properly apply several coats of hazardous chemicals which involves lots of waiting in between. While these browning and bluing are still often found on classic style firearms we have come a long way in the field of firearm coating applications.
Modern coatings still have their process of application but are not nearly as drawn out as traditional methods. Today we're going to discuss five common types of coatings, their process and their purpose. Those five are mil-spec Hardcoat Anodized, Cerakote, TiN (titanium nitride), NiB (nickel boron) and Black Nitride.
The purpose of coating is to protect the firearm from external hazards. Let’s take a look at five of the top choices filling the market niche right now. There are many pros and a few cons - you can make your own decision based on your intended use and preferred aesthetics. As long as you have a proper coating to protect it from corrosion, light to hard dents and dings, you can't go wrong with the strength and protection all five of these coatings have to offer:
Mil-Spec Hardcoat Anodized for Aluminum Components
If it's good enough to be used by the military for the past 60 years it's probably good enough to be used by most of us who take our rifles out to the range only a few days a week or maybe even only once or twice a year. Mil-spec Hardcoat Anodize is for aluminum components such as an AR15 lower receiver.
Hardcoat anodize is applied through electrolysis. Using a bath of nearly freezing sulfuric acid as an electrolyte, a completely cleaned and deoxidized aluminum lower is converted into an oxide film - when submerged into the bath, the lower has 100 volts and 24-36 amps of electrical current applied to it for the electrochemical process to bind the anodizing to the aluminum surface of the lower receiver.
The result is what we're usually familiar with in quality AR lower receivers which tend to be judged by abrasion resistance, wear resistance, corrosion resistance and enhanced aesthetics. Due to its surprising thin layer, with a thickness of only 0.75 - 1.0 mil (with half of that under the surface of the metal from the conversion process) the dimensions, fitment and tolerance aren't affected just like how the coating is on our Type III Hard Anodized Billet AR-15 80% Lower Receiver. This is important when considering the installation of components like the fire control group, upper receiver and take down/pivot pins for tight tolerances that enhance the feeling and performance of a rifle and not hinder it.
Cerakote (Can be Used on Nearly Everything)
Unlike the hardcoat anodizing process, which is only for aluminum components, Cerakote can be used on nearly anything including parts and accessories made out of polymer or even expensive optics. If you want a rifle that carries its color from buffer to muzzle all you need is a spray gun, sandblaster and an oven big enough to hold the parts for baking. Don’t let that scare you off though because there are plenty of companies that can Cerakote your items and quite strict guidelines on how they must do it if they want repeated business. Or you can choose from our selection of coated 80 percent lower receivers like OD Green Cerakoted Billet AR-15 80% Lower Receiver - just to name one of several colors we offer.
Cerakote layers are extremely thin; pretty on par with the thickness of hardcoat anodizing. Its layer is usually around 1.0 mil, a thousandth of an inch. Unlike anodized surfaces, Cerakote is tougher and lasts longer over time even with heavy use. Parts that have extremely tight tolerances, like high performance triggers, are recommended to stay in the original color you bought them in. Obviously, no coating lasts forever but Cerakote certainly can last much longer than anodized surfaces, provided you don't intentionally beat on your gear and chuck it on the ground all the time, your Cerakoted products could very well last a lifetime if taken care of.
Titanium Nitride (Brings Hardness and Shine)
For those that prefer a more flashy look, something away from the dark drab of flat, tactical colors; look no further than TiN. That stands for titanium nitride and it has been used on hard-use tools for years. Naturally, it's made its way to the firearms world. You know those “gold” AK’s you see everywhere? Bet you some big bucks those were probably TiN coated and not actually 24k gold. If you want to know how its applied, you’re going to want to get a PhD in Molecular Engineering due to the involvement of atoms, plasma, vacuums, vapors and more in the application process (kidding).
Titanium Nitride is an extremely thin and hard material. There are not as many color variations available with this process as there are with cerakote or anodizing but there is a substantial spectrum of color variations.
Most of the commercial uses for Titanium Nitride are for precision cutting instruments such as drill bits. It provides a harder external surface than steel, titanium alloys, aluminum and carbide. Due to its hardness and extraordinary thinness, it is appropriate for and often used on moving parts with high tolerances such as fire controls (trigger, hammer) and bolt carrier groups.
One more check mark in the pro’s column - TiN is slick while not being slippery, sticky or wet like bottled lubrication. Moving parts glide along TiN coated surfaces with very little friction without lubrication. This makes cleaning much easier! Virtually any and all metal furniture or components you have on your rifle can be coated in Titanium Nitride, including the barrel.
Nickel Boron (Offers Corrosion Resistance and Reduces Friction)
Now we’re getting into the single-color choices. With Nickel Boron (NiB) you get exactly what you’d think, a Nickel plating (basically silver). What it lacks in color pallet options it more than makes up for in its physical qualities.
The process of applying NiB is pretty straight forward if you are familiar with electrolysis. An AR bolt carrier group (BCG), for example, would be placed in a vat of water containing Nickel Salts and a reducing agent containing Boron. Electricity is applied. A thin hard coating of NiB builds up and re-structures itself to then bind onto the exposed surfaces. Much like TiN coatings, NiB is extremely thin with high lubricity making it a perfect coating for moving parts with high tolerances which is why you find it on thousands of bolt carrier groups.
Having a near mirror finish on your BCG isn’t a bad thing either, it makes carbon build-up extremely visible and easier to clean off. Plus, the shiny does look quite nice sometimes. A lot of builders like to polish various gun parts to look like they were NiB coated but in reality many "polished" parts are just raw exposed metal which means to protect them from external factors they have to remain well-lubed most of the time. Better to have NiB from the get-go for optimal performance and protection of your firearm parts.
Black Nitride (A metal treatment, not a coating)
Having read through the top 4 coatings, you may have notices some are only exterior coats while others penetrate the metal surface and build up on the outside and slightly into the surface. Black nitride is technically a metal treatment and not a coating as it is a chemical process whereas anodizing is a coating that is done on top of surfaces that have already been prepped or treated in some form or fashion.
Black nitride is similar to case hardening in that it strengthens the metal surface substantially without the wavey blue-brown-silverish coloring. Nitrogen and carbon are diffused into the surface to seal and create a hardened corrosion resistant surface which means that black nitride is better than parkerizing since there isn't a way for rust to build up between coating and surface.
Similar to NiB coating, the color choice is limited to only one and in this case that's matte black. That’s not such a bad thing though, especially if you enjoy being part of the “Black Rifle” club. Satire aside, if you're in the market for the best bang for your buck parts - black nitride is really great because it just does it all, looks low-key and aesthetically pleasing while still providing corrosion resistance, wear resistance and holds a low coefficient of friction creating exceptional lubricity.
What's the best coating?
Everybody wants to know what’s the best thing in the gun world, even though most of us rarely listen and just go with what we like or briefly read out. Coatings are no different. If you are looking for a coating in the first place you already understand one very important part of firearm ownership, taking care of your firearm. A coating on any metal surface has one major reason for existence, protection from external hazards, corrosion and impact. Everything else like color is secondary. Make your choice based on your use.
If you are hard on your firearms for extended periods of time, go for a harder coating that fuses with the metal like NiB, TiN or Black Nitride. At the same time, understand what components you are applying the coating to because some can and can't be used on moving parts for the sake of reliable functionality.
Having a coating like cerakote or hardcoat anodize on aluminum parts like your lower are great choices if you're going for a one-of-a-kind, personalized firearm. Look through our extensive catalog of 80 Percent Lowers that are coated in hardcoat anodize, cerakote, or bare for you to coat however you choose.
Get Your Next Pre-Coated 80 Lower from 80 Percent Arms!
Looking to get started on a rifle with a little more flair? Here at 80 Percent Arms, we offer a multitude of options. With options comes the ability to personalize your rifle beyond your imagination. Don’t feel like you are limited to one or the other. You can choose lowers that come already anodized in a few different color ways or even get some custom work done to it after the fact by anodizing your metal parts and have the rest of your furniture, (handguard, lower, etc.) in Cerakote. Maybe even try Cerakoting yourself at home!
Your options are limited only by your imagination. Search through our inventory of 80 Percent Lower Receivers that are hardcoat anodized or Cerakoted. Get started today and you’ll be one step ahead on your project. We also have everything you need to complete an 80 percent lower when you check out our 80 Percent Lowers Jig page, from jigs to routers and milling bits. Or you can save yourself the headache and just buy that peace of mind with the All You Need Kit.