firearm handler | types of gun finishes

Good finishing is imperative to keep firearms functioning properly and in pristine condition, protected from the elements, corrosion, and wear-and-tear from regular use.

Given the firearm industry’s stringent requirements, consistent high-quality firearm finishing is crucial to a successful project. With over 35 years of experience, Silvex provides advanced plating technologies to many of the industries prominent firearms manufacturers. All of our firearms finishes comply with military specifications.

As an industry leader, we are specialized in a variety of firearm finishing treatments, including black oxide, zinc and manganese phosphate, hard anodize, electroless nickel and Teflon. Below, we review these three types of gun finishes, their characteristics, and the benefits associated with each to help guide you in choosing the ideal treatment for your firearm.

Black Oxide (Bluing)

Black oxide finishing, also commonly referred to as bluing, is a traditional way to finish steel that protects firearms from corrosion while reducing glare, if properly pre-finished. The black oxide finishing process oxidizes metal surfaces and is achieved by an electrochemical reaction that transforms surface iron to magnetite.

The black oxide finishing treatment is a high-quality, corrosion-resistant finish that won’t chip, peel or change the physical dimension of a firearm piece. As one of the least expensive corrosion-resistant finishes on the market, black oxide is often the preferred finish used on gun barrels and small components. Gun oil is important to this type of finish to avoid rusting. Methods used are either a hot or cold process. Silvex offers the hot black oxide process in accordance with Mil-DTL-13924.

Hard Anodize (Hard Coat)

Type III Hard anodize, commonly referred to as hard coating is an electrochemical process that is performed by submerging an aluminum item in a chilled sulfuric acid bath that results in a hardness of 330 to 450 vickers. However, unlike black oxide, hard anodize results in a dimensional increase of the parts treated. The hard anodize process thickens the oxide layer by 50% on the surface of the base metal and penetrates the base metal by 50%, therefore tolerances need to be adjusted accordingly.

Other benefits of hard anodize in addition to hardness include abrasion and corrosion resistance. The natural color will vary from tan to dark gray depending on the alloy of aluminum. Most firearms products are coated to a thickness of .001 +/- .0002 and dyed to a black color then sealed in either hot water or a nickel acetate solution in accordance with Mil-A-8625 Type III.

Manganese Phosphate (Parkerize)

Phosphate coatings, also commonly referred to as Parkerizing, is a conversion coating done on steel that requires submerging a firearm in a phosphoric acid solution. Phosphate parts are self-lubricating in that the porous nature of the phosphate finish allows the oils to seep into the phosphate coating and become interlocked after drying. Coatings of manganese phosphate are a heavy crystalline finish that is measured by coating weight, a minimum of 16 grams per square meter.

Other benefits of manganese phosphate include its superior corrosion protection in comparison to black oxide, as well as it’s anti-galling and self-lubrication properties which provide continuous protection on gun parts subject to wear. Silvex offers manganese phosphate coatings in Mil-STD-171, Mil- DTL and DOD-16232 specifications.

Silvex is proud to provide the expertise and services that allow our customers to achieve their goals utilizing our various types of gun finishes. With our experience and investment in the firearms industry, commitment to providing certified quality finishes, outstanding customer service and lead times, look no further than Silvex for all your gun finishing needs. Have questions about our surface treatment services? Contact us today!