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September 12, 2020

What are the Different Types of Metal Finishes?

A type of metal finish

What are the different types of metal finishes?

  1. Metal Plating
  2. Blasting
  3. Basic Coating
  4. Powder Coating
  5. Abrasive Methods

Aside from being the final step that solidifies what a piece of metal looks like, a metal finish also provides numerous extra features to an already decently strong and customized steel. There are many types of metal finishes, all of which are applied with a specific intention in mind. Some of the more notable effects of metal finishes include higher general resistance, increased durability, and even enhanced electrical conductivity.

With that in mind, metalworkers, and those who deal with metals should be knowledgeable of their options when it comes to metal finishes. Take a look at these different kinds of metal finishes that may be suitable for multiple metal products!

Metal PlatingClose up photo of metal plating

This type of finish uses a chemical bath to change up the surface of the metal with thin layers of other metals. Most of the metals used include cadmium, chromium, nickel, and zinc. Metal plating is most often used to apply numerous extra features to the metal. In particular, the layer of extra metals improves the product’s overall resistance. It also increases the product’s durability by protecting the base metal from corrosion, chemical damage, and wear and tear.

This finish makes use of an electroplating method that generates an electric current to coat the base metal. Afterward, an electroless plating uses an autocatalytic process to help stabilize the reaction. The whole process is chemically intensive and complex; thus it can only be done by specialized metal plating services. Most things that need metal plating are machine tools and drills.

Blasting

There are two types of blasting methods for metal finishes: sand-blasting and shot peening. Sand-blasting is used in projects that require a very uniform matte texture. The process involves abrasives such as sand and metal pellets being forced onto a base layer at high speeds. Once the process is finished, it results in a smooth and clean product texture that is most evident in soft metals.

Shot Peening, on the other hand, uses compression to apply stress to the surface of the metal which in turn will improve its fatigue resistance, stress corrosion, and cracking resistance among others. This is done using a cold working process wherein compressive stress is applied to all surfaces as a way of counteracting tensile stress that naturally occurs during the manufacturing process.

Basic Coating

Basic coating process for metal

This kind of metal finish consists of simple water and oil-based paints. They are used to apply a light and inexpensive protection to the metal. It mostly protects against corrosion. Though if the metal itself is strong enough, a layer of paint would be more than what is needed.

Powder Coating

This finish is similar to paint, however, its application provides greater durability. The process of powder coating involves heat curing of dry thermoplastic polymer powder onto the metal. This produces one of three visual effects: a textured, matte, or glossy coating.

One of the benefits of using powder coating is that it can easily hide any defects on the base material. The process of affixing the powder is strong and accurate enough to superimpose on any rough patches in the substrate.

Abrasive Methods

A man buffing metal for a project

Four methods use primarily abrasives: polishing, buffing, honing, and lapping. These methods are mostly used to reduce surface roughness in metals right after the machining process. The roughness found here is measured in micro-inches. Precision is very important in these methods. They are primarily used to smoothen the initially rough surfaces of mating parts simply by rubbing them against each other.

The more you reduce the surface’s roughness the bigger the increase in the metal’s luster! At the end of the day, these methods are purely used to improve the aesthetics of the metal.

Anodization

This finish is unique to aluminum only. It involves an electrolytic passivation process used to increase the thickness of the natural oxide layer of the product. An electric current is passed through the aluminum parts (in this process they are called the anode, thus anodization) and a cathode which is usually flat aluminum bars. This process increases corrosion and wear resistance, and it improves adhesion for paint and primer sand!

Key Takeaway

There are many types of metal finishes. Some are more common than others. Each metal finish brings about something different from metal products. Some focus simply on the aesthetics of the metal product while others introduce better properties. Thanks to these metal finishes, metal products can be coated by a layer of both protective and aesthetically pleasing materials. It opens up new and better possibilities for both metal manufacturers and suppliers!

Bear in mind the different kinds of metal finishes mentioned above and discover which one is either essential or a must for the metalwork that you will be doing in the future. Know and understand how each of them is applied and what they provide!

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