Understanding the Types of Metal Finishes

May 10, 2022

Following fabrication many metal components undergo metal finishing, which entails treating the metal’s exterior surface with a thin layer of augmenting material. Metal finishing is an important part of the manufacturing process because it can enhance the metal product’s properties in different ways. At USTEK, we offer a variety of finishing services to make sure your metal components are prepared for assembly to your specifications.

metal finishes

Types of Metal Finishes

Depending on your application, there are several types of finishes to choose from that have different effects on various metal substrates. The following are some of the metal finishes we offer at USTEK.

Anodizing

Anodizing involves converting a metal’s surface into a thin oxide layer. The resulting oxide layer is thinner than other types of finishes for metal, but it offers superior durability and corrosion resistance. Aluminum substrates most commonly undergo anodizing.

Black Oxide (Hot Blackening)

Hot blackening adds a thin black oxide layer to the surface of a metal product, creating a matte black finish that resists abrasion. The metal is put through multiple tanks containing coolants, caustics, and cleaners that perform the hot finishing process. Many steel firearms, tools, and auto parts rely on hot blackening to protect them from corrosion.

Electro-Polishing

The process of electro-polishing removes metal ions from substrates. The metal is submerged in an electrolyte bath with an electrical current, which removes ions, rust, and defects. The final product has a clean, smooth appearance.

Painting

Painting entails applying liquid paint to metal surfaces. A paint finish typically consists of pigment, resin, and solvent. The pigment lends color to the finish, while the resin helps bind the coating to the surface and enhances part durability.

Plating

Also known as electroplating, plating applies a finish made of another type of metal such as tin, copper, chromium, or zinc. The process first coats the substrate with a negatively charged electric current, then puts it into a positively charged solution containing the desired metal ions. Metal plating enhances the metal’s corrosion resistance, coefficient of friction, durability, and aesthetic appearance.

Polishing

The polishing process reduces the metal surface’s roughness while increasing its luster, since light scatters less when it is reflected on smooth surfaces. Polishing can be done automatically or manually with different types of abrasives, depending on the condition of the metal substrate. Generally, a rougher abrasive removes larger surface imperfections, and then a finer abrasive smooths out smaller details.

Powder Coating

Some applications may use powder coating in lieu of liquid coating. The process involves electrostatically charging the substrate, attracting the powered particles to the surface. Powder coating creates a thicker layer of paint compared to liquid coating. It also features different curatives, pigments, flow modifiers, level agents, and other additives that provide additional protection and visual appeal.

High-Quality Metal Finishes from USTEK

All of the above finishes are available at USTEK, where you can find a high-quality part finish for nearly any type of metal component. Based on the needs of your specific application, we’ll help you select the right finishing service for your products. To learn more about our finishing solutions and other capabilities, contact us today.