Different Aluminum Finishing Types and Their Surface Styles

Aluminum is a versatile material known for its exceptional strength-to-weight ratio, good thermal and electrical conductivity, and corrosion resistance. However, specific aluminum finishes may be needed for your project to ensure that the parts meet the intended application and design requirements. Therefore, it’s crucial to understand the types of aluminum finishing to choose the one that best fits your project’s needs.

Aluminum Finishing Types and Their Surface Styles

Importance of Surface Finishing for Your Aluminum Products

The treatment of aluminum surfaces is not only about looks; it’s also about functionality, durability, and the critical process of providing extra protection for aluminum products. This treatment can improve aluminum products’ corrosion resistance, hardness, and appearance. By enhancing these properties through different surface treatment methods, aluminum can be used in various applications, including interior and exterior design, transportation, consumer electronics, and more.

Advantages of Aluminum Surface Treatment

Aluminum surface treatment provides numerous advantages, enhancing its suitability for various applications.

Enhanced Surface Smoothness: Surface treatment can improve the smoothness of aluminum sheets, providing a solid base for subsequent processing or applications.

Improved Corrosion Resistance: Specific surface treatments can protect aluminum from environmental damage.

Aesthetic Appeal: Aluminum can be given different colors and textures through various surface treatment methods to meet design requirements.

Increased Hardness: Certain treatment methods can enhance the hardness of the aluminum surface, increasing its durability.

Advantages of Aluminum Surface Treatment

Types Of Aluminum Finishes

Product designers and manufacturers utilize various surface finishes for aluminum parts, each with unique properties and practical uses.

As Machined Finish

The as-machined finish is an aluminum part’s original condition after being machined. This finish does not incur additional costs for surface finishing and is commonly used for applications that do not require a specific mechanical or chemical finish.

Aluminum CNC machining produces parts with a machined pattern surface roughness ranging from Ra 0.2 – 3.2µm, depending on the specific application requirements. The as-machined aluminum finishing is able to meet tight tolerances accurately. However, it’s important to note that your aluminum parts may display visible machine tool cutting marks.

Powder Coating

Many product designers use powder coating to achieve vibrant, long-lasting colors with high UV resistance. In this process, aluminum parts are cleaned and prepared before spraying with dry paint powder using an electrostatic gun. The coated parts are then baked to melt and cure the coating, resulting in a smooth finish.

Powder coatings may not be as hard and durable as anodized aluminum, but they provide an excellent appearance and strong corrosion resistance as long as the coating remains intact. The powder coating is also more environmentally friendly than liquid painting, which often involves solvents containing volatile organic compounds (VOCs).


Anodizing is a process that creates an anodic film on aluminum, metal, or alloy. The process chemically oxidizes the surface of the metal with oxygen, changing its properties. Anodizing provides increased corrosion resistance and better adhesion for paint primers and can create porous structures that enhance dielectric strength. It also improves the appearance of the metal, allows for sealing against moisture and other elements, and makes the surface harder.


Sandblasting is a commonly used mechanical finishing process for aluminum. It involves using a bead blaster to propel abrasive media such as steel beads or fine glass at high pressure against the surfaces of aluminum products. The beads remove impurities from the aluminum surface, producing a smooth, bright, clean finish.

This surface treatment often gives aluminum components a “satin” or “dull” finish. Bead blasting is suitable for achieving a semi-polished, textured surface on aluminum products. It retains the material’s base color, providing a brighter surface finish.

Alodine Finish

Alodine finish, or chem film, is an aluminum surface finish used to passivate oxide film on aluminum products. This process involves immersing the aluminum piece in a collected chemical bath for a specific duration, allowing the alodine film to develop on its surface.

This aluminum surface treatment is more cost-effective than anodizing and improves corrosion resistance for aluminum machined parts. While chem film is not as complicated or wear-resistant as anodized coating, it is suitable for specific applications that require high electrical conductivity.


Electroplating is used in the manufacturing industry to apply a thin metal coating, such as copper, silver, gold, nickel, titanium, zinc, or chromium, to the aluminum surface through electrolysis. This additional layer enhances the aluminum’s chemical, mechanical, and physical properties, improving its conductivity, strength, and resistance to UV light, abrasion, and corrosion. This method allows for customizing the properties of aluminum to suit specific applications.


Brushing is a mechanical aluminum surface finish created by moving an abrasive brush over the surface of extruded aluminum. This treatment adds style and quality to various products. Due to its weather resistance, brushed aluminum finishes are mainly used for car bumpers, modular frameworks, and commercial signage, making them suitable for indoor and outdoor signs.


Aluminum polishing is an excellent way to enhance your aluminum products’ aesthetic appeal, functionality, and durability. This process helps prevent contamination and oxidation, which can degrade the surface of aluminum components over time due to exposure to elements like wear, oxygen, and high temperatures. It also creates a reflective surface that protects the aluminum from corrosive substances.

Polished aluminum offers several advantages compared to other surface treatment processes. For example, it can provide a more brilliant and smooth surface than anodizing or painting. The high reflectivity enhances the product’s visual appeal, adding a sense of luxury, and also meets hygiene standards for applications in industries such as food and medical devices, where polished surfaces resist dirt accumulation.

Bright Dipping

Bright dipping is a process used to create a highly shiny surface finish on aluminum parts. This is achieved by immersing the parts in acid, which smooths out the microscopic imperfections on the surface of the extruded aluminum to produce a “mirror-like” finish.

While bright dipping may be necessary for certain products, it is essential to note that this process can be potentially hazardous and environmentally harmful. Additionally, bright dipping is most effective when used with specific grades of aluminum, particularly 6463.

Chemical Etching

Chemical etching creates intricate patterns and textures on aluminum surfaces, giving aluminum products a unique visual effect. It is considered an ideal solution for aluminum processing. Chemical etching is a subtractive process that precisely removes material using controlled chemical reactions without applying pressure or heat, thus preserving its properties.

Types Of Aluminum Finishes

Various Surface Effects and Styles for Aluminum Finishes

Aluminum alloys can be highly customized to suit the requirements of specific applications. Below are the various surface finishes and styles used by product designers.


Satin finishes provide a slightly glossed surface finish. Although they offer lower reflectivity than a high-gloss finish, they are usually smoother than matte finishes. Therefore, they are a suitable middle choice for aluminum parts that do not have a preferred finish style. For example, the brushed finish provides a satin-like finish for furniture and architectural designs.

A satin finish typically has a 72 GU gloss rating. It perfectly conceals flaws and allows for easy cleaning. Additionally, unlike high-gloss finishes, satin does not retain fingerprints or watermarks.

High Gloss

A high-gloss finish provides a smooth, aesthetically appealing surface with impressive light reflectivity. Regardless of the color, high-gloss finishes are typically shiny.

Aluminum polishing is a common finishing option that creates this high-gloss surface effect for aluminum automotive parts, architectural elements, and consumer electronics. However, dust, fingerprints, and watermarks may be more noticeable on a high-gloss finish than on other aluminum finishes.


A metallic finish gives aluminum products a luxurious feel. This finish has low reflectivity compared to a high gloss finish. Brushed or clear anodizing creates a metallic surface for aluminum products such as decorative metal parts, nameplates, and signage.

Additionally, you can tint this metallic finish to resemble brass, copper, gold, stainless steel, and silver. While metallic finishes are more prone to retaining watermarks and fingerprints, they are visually appealing and easy to clean.


This type of aluminum surface finish creates a flat, non-reflective look with a gloss rating of 30 GU. It effectively hides watermarks and fingerprints and is cost-effective because it requires fewer coating layers. You can achieve a matte finish for aluminum parts and components through anodizing and powder coating. Matte finishes are long-lasting, resistant to tarnishing, and easy to clean. However, they may appear less polished than glossy or satin finishes because they need shine.

Various Surface Effects and Styles for Aluminum Finishes

How to Choose The Right Aluminum Surface Finish

When selecting an aluminum finish that best suits your product, you should consider several factors.

Corrosion Resistance

Liquid paint provides the best corrosion resistance for aluminum parts, followed by anodizing and powder coating. While sublimation does not offer the same level of corrosion resistance, using the correct type of dye can still provide effective protection against corrosion.

Intended Application

Determining whether the aluminum parts will be used indoors or outdoors is important. Aluminum products for outdoor use typically need a specific surface treatment that can withstand UV radiation, corrosive substances, and temperature changes.

For outdoor applications, it’s recommended to use an aluminum surface finish such as anodizing, electroplating, or alodine finish to ensure chemical resistance if the product is exposed to corrosive elements. Additionally, it’s crucial to assess whether the aluminum components will be subjected to significant wear and tear, such as impact or abrasion.


Selecting a finish compatible with the specific aluminum alloy used for your extrusion is important. Many finishes are available for different alloys, so finding one that matches your aluminum is easy. For instance, liquid paint, due to its dark finish, has been used on aircraft parts for years. It offers excellent protection against corrosion from exposure to water vapor and other environmental factors.

Desired Aesthetics

Consider their aesthetic requirements when choosing a surface finish for your aluminum parts. Different finish options offer a variety of colors, textures, and gloss levels to meet your specific needs. For instance, aluminum parts with a mill finish have a dull appearance with visible tooling marks. On the other hand, bright dipping can provide a mirror-like finish for your CNC aluminum parts. Additionally, some finishes offer different colors and textures to match the requirements of your projects. Therefore, it’s important to carefully assess the aesthetics needed for your specific application to select the most suitable surface finish.


Different finishes have varying costs, determined by the type of aluminum alloy, the quality of the finish, and any additional metal plating needed. Anodizing tends to be the most expensive, followed by powder coating, liquid paint, and sublimation, which are all less costly options.


Different finishes offer varying levels of durability. Liquid paint provides a more durable finish than powder coating, although less long-lasting than anodizing or sublimation. Powder coating is a popular choice because it is durable and provides additional protection against corrosion and chips compared to liquid paint.

Surface Treatments For Your Aluminum Parts

Enze is your ideal manufacturing partner for surface treatment services for aluminum parts. We offer a range of aluminum finishes, including anodizing, polishing, powder coating, and brushing, at competitive prices. In addition to our surface treatment expertise, we provide reliable manufacturing processes such as sheet metal fabrication, CNC machining, 3D printing, die casting, and rapid tooling. Our team will closely collaborate with you to understand your project requirements, ensuring that the production and surface treatments are applied precisely and consistently.


When designing your product, it’s essential to consider the aluminum finish carefully. The chosen finish will impact the metal’s durability, corrosion resistance, and longevity. Additionally, different finishes can affect the cost of production, as they may require additional materials or processes for proper application. Therefore, it’s crucial to evaluate which finishing process best aligns with the specific needs of your design before making a final decision.