Nitride vs Phosphate Finish – A 2022 Guide

Are you struggling to decide between nitride and phosphate finish for your next gun purchase? Are you wondering which of these two finishes is the hardest? And which offers the most corrosion resistance to keep your gun looking and working great?

In this article, we will be exploring all the differences between the two finishes to help you decide which one will serve you best. Will it be the option with the most robust surface? Or the one that holds gun oil the best? 

Photo credit: ar15.com

Join us as we take a look at the benefits and disadvantages of each. We will also look at each of the characteristics in more detail to help you find the best finish for you.

TL;DR: Nitride vs Phosphate Finishes

Nitride Finish

Phosphate Finish

Pros

Pros

Durable

Durable

Easy to clean

Mil-Spec

High corrosion resistance

Economical

Cons

Cons

Shiny look

Difficult to clean

More expensive

Requires more lubrication

Best For

Best For

For the person who wants an easy-to-clean gun with a smooth finish that will last for many years.

For the person who likes a textured finish, good look, and military nostalgia.

How is a Nitride Finish Applied?

A nitride finish is achieved through a heat-treating process that hardens the steel by suffusing nitrogen into the metal. There are a few steps to this process, starting with a salt bath nitrocarburizing cycle. 

These salt baths are also known as ‘Tenifer’ or ‘Melonite.’ The temperatures of these salt baths range from 1000℉ (usually Tennifer method) to 1600℉ (usually Melonite method). The higher temperatures of the salt baths lead to thicker nitride layers. So, a Tenifer nitride finish will be thinner than a Melonite finish.

After the salt bath, the piece goes through various polishing processes. This second process includes vibratory finishing, lapping, and also center-less grinding. After this process, you will have a mottled gray surface.

The last step is another immersion, this time in a hot potassium nitrate bath, which oxidizes the last remaining iron on the surface. This also takes the gun from mottled grey to a deep, shiny black.

This finish is smooth and very hard. This increase in hardness will make your gun more resistant to erosion, dents, and nicks and much easier to clean. With the nitride finish, you also do not need chrome lining, as the gas key and inner areas of the bolt carrier are also treated. A nitride finish will not hold lubricants well due to its smooth surface.

Photo credit: smith-outfitters.com

How is a Phosphate Finish Applied?

There are two main types of phosphate finishes: zinc phosphate and manganese phosphate. This process is a chemical conversion coating that is applied to the surface of the steel. This process can also be referred to as ‘parkerizing.’ The technique was popularized by the Parker Rust-Proof Company, now known as Henckel.

Parkerization starts with submerging the metal parts in an aqueous bath of phosphoric acid solution. The temperature of this bath is kept under 250℉. Once completely submerged in the solution, streams of bubbles will start rising from the metal parts. Once the stream of bubbles has stopped streaming, you will know the process has been completed. This usually takes about 30 minutes.

The color of the pieces, once phosphatized, will vary from medium-grey to black, depending on which ingredients were used. 

A phosphate finish is mil-spec, meaning that it meets military specifications. This makes guns with a phosphate finish popular as military weapons. This finish is durable and erosion-resistant. The surface is slightly textured, meaning that it holds oil very well. However, this texture on the body can make cleaning more difficult. 

Relevant Characteristics Between Nitride and Phosphate Finish

Nitride Finish

Phosphate Finish

Hardness

64 HRC

42 - 46 HRC

Smoothness

Very Smooth

Textured

Corrosion Resistance

Best

Good

Wear Resistance

Best

Good

Ease of Cleaning

Best

Decent

Lubrication

Good

Best

Price

More expensive

Affordable

Similarities and Differences

Both of these finishes are excellent options and have many benefits for the user. We will now take a closer look at each of these finishes and discuss their similarities and differences. At the end of the article, you should know which of these two finishes would suit you and your lifestyle the best.

Nitride and Phosphate Finish Differences

The table above clearly and easily reflects the difference between these two finishes for a quick reference. Next, we will compare the most significant differences between these two finishes in more detail below.

Smoothness

Besides being aesthetic, the smoothness of your gun will impact how easy it will be to clean. The process of nitriding results in a very smooth finish inside and out. This makes the cleaning of a nitride finish gun very easy. At the same time, a phosphate finish is more textured and thus more challenging to clean. 

Ease of Cleaning

Cleaning your gun is essential to ensure it remains in good working order. The more textured phosphate finish requires more cleaning because it is more porous, and dirt can get stuck more quickly than with a smooth nitride finish. Therefore a phosphate gun will need more regular and thorough cleaning.

Lubrication

Lubricating your gun with gun oil is done to keep your weapon clean and, most importantly, to keep rust from forming on your gun.

The more porous texture of phosphate means that it holds the oil much better but will require more oil per cleaning. The nitride finish, with its very smooth surface, does not hold oil very well but requires less oil per cleaning.

Price

Nitride Finish (Photo credit: ar15.com)

Phosphate is a much more straightforward and cost-effective process, and therefore a phosphate finish is usually much more affordable than a nitride finish. Bear in mind that we are just comparing the cost of a phosphate finish vs. the price of a Nitride finish and not the addition of a chrome-lined barrel.

Nitride and Phosphate Finishes Similarities

Next, we look at the characteristics mentioned in the above table that are similar between the two finishes and what they bring to the table.

Hardness

The hardness of the finish will determine how easily it will pick up scratches and nicks. The harder metal will also offer more protection to the barrel, meaning you won’t have to replace it as often. Both Phosphate and Nitride treatments provide excellent hardness. While seemingly different, both are improvements and differences will not be realize by most shooters.

Wear Resistance

Both of these finishes can give you a lot of use before you start to see the wear. Nitride can be handled a lot more before showing wear. In contrast, phosphate can start showing wear much sooner.

Corrosion-Resistance

Corrosion is the killer of guns. It can lead to malfunctions, affect the accuracy, and eventually ruin it completely. Both phosphate and nitride have good corrosion-resistance. However, nitride is slightly more resistant than phosphate. Phosphate needs to be lubricated with gun oil much more than nitride to keep rust specks forming on the outside and even the inside of your gun.

Black Nitride Finish (Photo credit: tacticalshit.com)

Advantages of a Nitride Finish

Are you considering a nitride finish for your next gun purchase? A nitride finish offers a few advantages that make it a great option to look at.

One of the best advantages of this finish is the hardness of the steel; at 64 HRC, nitride is just six units below a diamond finish at 70 HRC. This means that the metal is solid and durable. This increase in the metal’s strength also leads to longer barrel life as it is better protected.

Another great advantage is the nitride finish’s high resistance to erosion. This finish is designed to keep your gun lasting for many years. This also means that a weapon with a nitride finish performs well in areas with extreme temperatures, including cold, and places where the gun parts will be exposed to abrasives such as sand in the desert. 

A nitride finish’s smooth surface also means that the gun will be easier to clean. It will need much less lubrication to keep it in good working order. 

A nitride finish is a choice for you if you enjoy a gun with a smooth finish, and if you do not enjoy toiling with cleaning your weapon regularly. A nitride finish is meant to last, so if you want a gun with a finish that will last for many years to come, then the nitride finish is a good option for you.

This finish will be right for you if you are looking for a long-lasting and durable weapon. If you live in an area with extreme temperatures, you will be thankful for the harder steel and higher erosion resistance. Additionally, if you are the type of gun user who wants the cleaning to go fast, a nitride finish will be the ideal solution for you. 

Photo credit: americanbluing.com

Advantages of a Phosphate Finish

A phosphate finish is nostalgic as it has been the chosen finish of the US Military for many years and, as such, has earned the respect of many service members. 

A phosphate finish is a tried and true method of treating your gun. It follows military specifications, which makes it reliable. Since this method has been practiced for so long, you can trust that it is a quality finish.

The look of the phosphate finish is also very appealing. It comes in grey and a deep black, and there is at least one service that offers this finish in traditional WWII Army green. This finish in the final product also does not appear overly shiny or cheap-looking.

Are you looking for the real deal? A proper mil-spec weapon that has stood the test of time and you know you can rely on? Then the phosphate finish is definitely the right choice for you if you don’t mind spending some extra time cleaning your gun to ensure it stays in excellent working order. 

There is a real nostalgia surrounding a phosphate finish that certain users like. After all, it was the finish used on guns during WWII. Phosphate is also still preferred by the military, so if you’ve served your country, you’ll most likely be accustomed to a phosphate finish.

What About Chrome Lining?

Chrome lining is an excellent option, especially when paired with a phosphate finish. The process of applying a chrome lining is to place the barrel’s breech into a chemical bath. Next, a moveable anode is placed in the bore of the gun. As the current passes through the chemical bath solution, the chromium from the bath is deposited on the inside of the bore.

Many gun users prefer using a chrome lining to improve the accuracy of the gun and make the barrel easier to clean. However, there is much debate over chrome-lined vs. nitride. Many users feel that with a nitride finish, you do not need the additional chrome lining. This is because the inside of the gun is also treated during the parkerizing process. 

Some users also feel that chrome lining can be quite inconsistent, and you may end up with a less than ideal lining, so if you are considering this as an option, make sure you use a reputable service.

A chrome lining is an excellent option to consider if you choose a phosphate finish. However, this can be quite an expensive option. If you decide to go with a phosphate finish with a chrome-lined barrel, it will likely cost more than a nitride finish without chrome lining.

Parkerizing (Photo credit: americanhandgunner.com)

Bottom Line

Although both of these finishes are very good, there are a few differences, as you saw above. These might influence your decision when deciding between one or the other. It will come down to what you prefer and feel is most important. Some people like to go for a more aesthetically pleasing gun. The nitride finish has a gleaming look, whereas the phosphate has a deep matte color. 

Some prefer a gun that is easier to clean and requires less oil to stay in good working order. In that case, the nitride finish might be more for you. However, the phosphate finish keeps oil much better.

In the end, it will depend significantly on what you will be using the gun for, as well as how regularly you will be using the weapon. Both of these will last for a long time and work well if you take care of them.

People Also Ask

If you are looking at these options, you may have additional questions that we haven’t covered yet. We will be answering a few of the most commonly asked questions below to help you decide which is best for you.

Is Nitride Better Than Chrome?

There is a considerable debate surrounding this topic, so you may have run into many different opinions. A lot of users prefer nitride and feel that it performs the same as chrome lining. However, nitride is much cheaper and is also more corrosion-resistant than chrome. 

Photo credit: criterionbarrels.com

Does Nitrided Steel Rust?

Nitrided steel is not rust-proof, but it does have very high corrosion resistance. If you take proper care of your nitride-finished gun, there is no reason why you should have to worry about rust for a very long time. Nitrided steel also lasts well in highly corrosive environments such as seaside towns or areas with a lot of sea spray.

Does Nitriding Add Thickness?

Nitriding is a thermal treatment to enhance the finish of your gun and add strength and corrosion resistance. As such, this treatment isn’t known for adding thickness.



Michael Lutes

Michael Lutes is the managing editor and owner at Gun Mann. He is a veteran, gun enthusiast, 3 gun competitor, and 2a advocate. Mike has a passion for innovation and education across the industry to create great content, training, and insights from the best and brightest.