Metals have played a key role in our lives for thousands of years. Metal is crucial to some of the most important components in a huge range of technological innovations. There are dozens of metals that we use on a regular basis, such as copper, tin, zinc lead and nickel. While each of these metals has its own strengths, they also have a range of inherent weaknesses. These need to be improved upon in order to make them suitable for their ultimate use. The process through which this is achieved is metal finishing.

What is metal finishing?

Metal finishing is the final stage of the metal manufacturing process. It’s used to reduce surface roughness beyond the capabilities of machining operation for parts that are needed to mate or seal. The process also includes methods of metal cleaning, deburring or descaling. It can also provide better aesthetics and environmental protection.

Why is metal finishing important?

Metals that are used in engineering and manufacturing will often not have the needed strength, durability or resistance to a range of outside factors that are needed for a particular application. To enable them to acquire these attributes, a finish or coating is applied to alter the properties of the metal and to give them a better performance.

What is the purpose of finishing

Finishing brings out a range of properties and qualities in the metal, making it more suitable for use in a variety of different applications. Finishing can increase the durability of the metal, enhance its electrical conductivity and improve its decorative appeal. It can also give the metal higher electrical resistance, higher chemical resistance and higher tarnish resistance.

In short, finishing gives the metal the quality it needs to help it better fulfil its application.

What are the methods of metal finishing?

There is a range of different finishing techniques for metal. These include:

Electroplating creates a metallic coating on the surface of individual pieces through chemicals and electricity.

Powder coatings can help to smooth out surface defects by applying a layer of durable melted plastic powder onto the metal.

Hot blackening uses a heated process to coat the metal and to make the surface highly durable. It’s used to enhance abrasion resistance and is best used with harder metals.

Vibratory finishing is sometimes used for large-scale projects. If speed is required for finishing numerous metal pieces, vibratory finishing is the best choice. It’s an ideal method if you have a range of surface defects that need to be removed.

Grinding is a highly skilled process that produces a wide range of finishes and can be more labour-intensive.

Sand-blasting works best for large flat surfaces requiring a matte finish with softer metals which are more easily formed by the sand.

Buff-polishing uses cloth on a polishing machine to create a rounded finish.

Brushing metal creates a uniform finish, with brushing merging the best of buffing and grinding, it smoothes out defects and creates a pristine surface.

What is a finishing process?

The finishing processes outlined above aims to alter the surface of a manufactured part in order to achieve a particular characteristic.