Metal Finishing: What’s The Right Coating For Your Components?

Introduction

Read this blog to discover the various types and advantages of metal finishes that can enhance the performance, appearance and longevity of your products.

Metal finishing surrounds us daily with an abundance of components.

From the expensive shine of jewellery to the resilience of nuts and bolts, numerous products, materials, and applications rely on metal finishing as that crucial end stage of manufacturing.

But what overall benefits suit your requirements, and which metal finish provides the best option for your specifications?

In this blog, we break down the essentials of metal finishes, the various types and what advantages they can provide for your needs.

What Are Metal Finishes?

Metal finishing is a process that consists of coating a metallic surface with an additional layer or removing material from the surface.

Often, in the final stage of manufacturing after metal fabrication, metal finishes can be used for various purposes, such as increasing material durability, reducing friction or applying corrosion resistance.

The term “metal finishing” can also be applied to “metal plating” or “coating”.

Electroplating is a common practice used for metal finishing, otherwise known as “electrochemical deposition” or “electrodeposition”. The process involves an electrical current depositing metal ions onto the component surface. While this method applies a layer, other metal finishes can remove metal ions to create a smoother surface or a more aesthetic appearance.

So, alongside electroplating and polishing, we have numerous forms of metal finishing and plating, such as passivation, cladding, case hardening, hot blackening, powder coating, blasting and more.

However, the metal finish you choose should depend on the overall application of your component, whether heat resistance or electrical conductivity.

In a sector worth over $96.10 billion in 2023, the metal finish market offers an essential service for multiple giant industries worldwide.

From automotive to aviation and civil engineering, metal finishing remains an essential service for numerous applications, structures and functions.

5 Benefits of Metal Finishing

Different metal finishes can provide various advantages depending on the purpose and application of the material. Here are five benefits of metal finishing:

1. Durability

With so many metal components defined for their strength and resilience while tasked with battling against the elements, improved durability becomes a significant advantage of metal finishes.

Everyday components such as tools, cylinders and mechanical parts require an extra layer of durability to enhance their quality and sustainability as products.

2. Corrosion Resistance

The number one enemy of metal is corrosion. As a defence tactic, most manufacturers finish their metal products with corrosion-resistant metal finishes to ensure they avoid rust, especially when regularly exposed to moisture.

3. Heat Resistance

Various industries require heat-resistant metal components, such as engineering for the aviation and automotive sectors. A silver-plating process can offer the highest heat threshold with metal materials such as titanium, stainless steel, and tungsten.

4. Conductivity

Metal components play an integral role in electrical applications. For example, gold plating or silver applications across various metal finishes can provide different degrees of conductivity. However, other metal finishes work in contrast to increase the resistance to electricity, such as anodising.

5. Appearance

Alongside the practical purposes of metal finishing, it can also enhance the appearance of materials. Powder coating, plating and silk screening are all metal finishing processes that will enhance the overall appearance of your components.

What are the types of metal finishes?

So, now we have a fundamental understanding of metal finishes and their benefits, what are the different types available:

Hot Dip Galvanisation

Also called “galvanisation” or “galvanising”, hot dip galvanisation is a metal finish technique used to protect iron and steel by coating it with zinc. The steel or iron component gets immersed in molten zinc, where a series of zinc-iron alloy layers form within a metallurgical reaction to provide a robust coating.

This unique metal finishing process is utilised for various applications, including construction, utilities, and transport. As a widely used metal finishing technique, the hot dip galvanising market was valued at $85 billion in 2022. Galvanised steel is an ideal metal finish for corrosion resistance, with the automotive industry proving a main contributor to its demand worldwide.

Pretreatment Primer

By combining two technologies into one process, pretreatment primers help protect metallics from corrosion while allowing excellent adhesion of inks onto more challenging substrates. Pretreatment primers also reduce general wear and tear, increase thermal stability and improve aesthetics.

As a metal finish, pretreatment primer helps increase the longevity of components like nuts and bolts in high-pressure hot conditions. The market size exceeds $11 billion, with a 5.1% CAGR predicted between 2020 and 2026.

Powder Coating

While many metal finishes are achievable in liquid form, powder coating uses powder to create a greater thickness than traditional liquid coatings. Various pigments, level agents, and flow modifiers can be added to the powder to provide the desired result, whether for appearance or protection.

The coating is typically applied with a spray gun before your component is cured in an oven to complete the chemical reaction that helps bind the coating and substrate.

Black Oxide Coating

The black oxide coating metal finish adds mild corrosion resistance alongside appearance and reduces light reflection. Rather than a deposit on the surface like other metal finishes, black oxide coating works as a chemical oxidation of the surface.

Often used on metals containing iron, black oxide coating can be used on other metals like copper and stainless steel.

Polishing

As a metal finish, polishing or electropolishing removes metal ions from the surface to create a smoother finish. Buff polishing is another metal finish technique that doesn’t apply the electrochemical process. Essentially, both metal finishes use an abrasive method to reduce surface roughness.

Speak to Metal Finishing Specialists

At Barton International, we’ve been pioneering global metalwork production since 1898. With expertise across supply chain management and custom steel fabrication, we proudly supply over five million parts annually across 20+ manufacturing processes.

Our metal finishing expertise includes services such as powder coating, pretreatment primer, hot dip galvanisation, and more.