What Is Electroplating? Process, Benefits & Applications
What is Electroplating?
Electroplating – also known as electrodeposition, is the process of using electricity to coat an object, often referred to as the substrate, with a thin layer of metal. It is a specific type of electrochemical deposition where a substrate (item to be plated) is the cathode, the metal being plated is called the anode, and both are placed in an ionic solution. This setup allows the metal to deposit evenly onto the surface. Electroplating is widely used to enhance components by altering their appearance, protecting them from corrosion, increasing their durability, wear properties, electrical conductivity, and overall appearance.
Karas has specialised in electroplating services for decades, delivering reliable solutions for customers across multiple industries. This page explains how electroplating works, the metals most commonly used, its advantages and limitations, and where the process is most widely applied.
Interchangeable terms
Sometimes, electroplating can also be described as electrolytic plating, industrial electroplating, surface coating, coatings, surface finishing, metal finishing or metal plating.
There is also some crossover when we talk about electrodesposition. Electroplating is a specific type of electrodeposition that focuses on adding a thin metal layer to the substrate. In contrast, electrodeposition encompasses a broader range of materials, including metals, alloys, and even polymers and is used for both functional coatings and repairs.
Introduction and history of electroplating
Electroplating has been a central component of industrial development for over two centuries. The invention of Alessandro Volta’s electric battery in 1800 made it possible to explore electrochemical metal deposition. In 1805, Luigi Brugnatelli demonstrated gold plating using a Volta battery, establishing the foundation for the modern technique.
By the late 19th century, the invention of the dynamo made electroplating commercially viable, driving widespread adoption during the Industrial Revolution. In the 20th century, new electrolytes and more advanced equipment enabled safer, more precise coatings, supporting industries such as electronics and aerospace. Today, electroplating remains a cornerstone of modern manufacturing.
For more detail, see our History of electroplating series, which explores the technique from its earliest methods through to its role in modern industry.
Electroplating process
The electroplating process works by electrodeposition, which means submerging the component/substrate into a chemical bath containing dissolved metal salts.
Key:
- Electrolyte
The liquid solution that carries the electric current. It contains dissolved salts of the plating metal, which supply the metal ions that form the coating. - Electrode
Any conductor connected to the power supply and placed in the electrolyte. In electroplating, there are always two: the cathode and the anode. - Cathode
The negatively charged electrode – this is the component being plated. The metal coating builds up on its surface during the process. - Anode
The positively charged electrode – often made of the plating metal itself. It dissolves slowly, topping up the electrolyte with fresh metal ions. - Ion
A charged particle. In plating, these are metal atoms with a positive charge (because they’ve lost electrons). They move through the electrolyte towards the cathode where they regain electrons and turn back into solid metal. - Direct Current (DC) Power Supply
The power source that keeps the whole process moving by pushing the metal ions in one direction.
How does the electroplating process work?
Anode
The anode is made of the metal that will be deposited onto the component. During electroplating, atoms from the anode dissolve into the electrolyte as positively charged ions, making it the source of the new coating.
Cathode
The cathode is the component to be plated, also known as the substrate. Connected to the negative side of the power supply, it attracts the positively charged metal ions, which are then reduced at its surface to form a solid, adherent metallic layer.
Electrolyte
The electrolyte is a carefully prepared solution containing salts of the plating metal. It acts as the medium that carries metal ions between the anode and cathode. The composition of the electrolyte – including additives that affect brightness, hardness, and grain structure – has a major impact on the quality of the coating.
Power Supply
A direct current (DC) power supply drives the entire process. By controlling voltage and current density, technicians can influence the thickness, uniformity and adhesion of the deposit.
Process Overview
When current flows, metal ions dissolve from the anode into the electrolyte. These ions migrate towards the cathode, where they are reduced and form a uniform metallic coating. The properties of the finish – such as thickness, adhesion and brightness – are determined by controlling factors including current density, bath composition, temperature and plating time.
When current flows, metal ions dissolve from the anode into the electrolyte. These ions migrate towards the cathode, where they are reduced and form a uniform metallic coating. The properties of the finish – such as thickness, adhesion and brightness – are determined by controlling factors including current density, bath composition, temperature and plating time.
Quality
Adhesion is one of the most critical measures of plating quality. A coating that does not properly bond with the substrate can delaminate, peel, or flake under stress, rendering it ineffective. In industrial applications, the plated layer must behave as an integral part of the component, achieved through rigorous surface preparation, activation, and controlled deposition. Poor adhesion may be of little consequence in consumer goods, but in high-performance environments, such as aerospace fasteners, power distribution busbars, or automotive safety parts, the consequences of coating failure can be severe.
Common electroplating techniques
Barrel Plating
A highly efficient method for processing large batches of small, durable items such as fasteners, screws and pins. Parts are placed in a rotating barrel immersed in the electrolyte, which allows for even coverage across the entire batch. Barrel plating is valued for its cost-effectiveness and speed, making it a popular choice in industries where small components are required in high volumes.
Rack Plating
Rack plating is suited to larger, more delicate or complex components that require careful handling. Items are mounted on racks to ensure secure electrical contact and to achieve uniform coating, even across intricate geometries. Rack plating is frequently used in aerospace, automotive and electronics applications, where precision and finish quality are essential.
Learn More About Rack and Barrel Plating at Karas
Brush Plating
An adaptable technique used for localised plating, repairs or touch-ups. A conductive brush saturated with electrolyte is applied directly to the area being coated, offering precision where full tank immersion is impractical. Brush plating is particularly useful for oversized parts, in-situ repairs, or when only targeted sections of a component need treatment.
Automated Production Plating Lines
Automated systems integrate cleaning, plating, rinsing and finishing into a streamlined process under tight control. These lines are well-suited for high-volume production where consistency and efficiency are paramount. As an example, Karas operates a fully automated silver electroplating line for copper busbars, ensuring repeatable quality and optimised throughput for demanding industrial applications.
Heavy Build Coatings
High-build plating, also known as heavy build coatings, is significantly thicker than typical commercial layers. This type of plating is utilised in demanding environments such as defence, oil and gas, medical, and power generation sectors. Over the years, we have supplied high-build silver plating for various contact components used in the National Grid. The benefits include protection of components from harsh chemical environments, increased durability, and the creation of fully pore-free, biocompatible surfaces.
Sacrificial Coatings
Sacrificial plating or coatings are protective layers made of metals more reactive than the base metal. These coatings corrode in preference to the substrate, thereby protecting it from corrosion. However, they are primarily designed for corrosion prevention rather than wear resistance.
Metals and substrates used in electroplating
Silver plating
Silver plating provides exceptional electrical conductivity at a lower cost than gold. It is used extensively in switchgear, connectors, and electronic components that require efficient signal transfer and wear resistance.
Copper plating
Copper plating provides excellent electrical and thermal conductivity. It is commonly applied as an undercoat to improve adhesion of subsequent layers and to produce a smooth, uniform surface. Copper plating is used extensively in electronics and as a preparatory layer for decorative or functional finishes.
Zinc plating & colour passivates
Zinc plating offers sacrificial protection against corrosion. The zinc layer corrodes preferentially, protecting the underlying steel. Passivation treatments can enhance appearance and resistance. Typical applications include automotive fasteners, brackets and components exposed to moisture or salt.
Tin plating
Tin plating delivers a bright, solderable and non-toxic finish. Tin’s ductility allows it to coat complex shapes effectively, making it well-suited to electronics, food-contact components, and parts requiring solderability.
Nickel plating
Nickel plating is valued for its hardness, durability and resistance to wear. It improves corrosion protection, reduces friction, and can deliver a bright decorative finish. Nickel is widely used in aerospace, oil and gas, and heavy industry where performance and longevity are essential.
Gold plating
Gold plating combines corrosion resistance with outstanding electrical conductivity. Its biocompatibility makes it suitable for medical implants, while its reliability ensures performance in electronics, aerospace and high-end decorative applications.
Applications and industrial use cases
Everyday Examples of Electroplating
Electroplating is widely used, and you are likely to find it applied in everything from electronics to car components.
- Kitchenware (cutlery, taps, pots & pans).
- Mobile phones & electronics (gold/silver contacts).
- Coins & currency (nickel, copper layers).
- Car parts (rims, fasteners, exhausts).
- Machinery parts (bearings, gears).
- Building structures (bridges, railings).
Electroplating has many everyday uses, but its primary role in modern living and advanced manufacturing lies in its application for engineering and industrial purposes.
Industrial
Electroplating helps manufacturers reduce their production costs as they can use affordable base metals such as steel, aluminium, or zinc and then applying thin coatings of more valuable materials to achieve the desired surface properties, such as corrosion resistance or conductivity, without the need to make the whole component from expensive, precious metals. This process delivers cost efficiency while preserving or enhancing the functional and aesthetic qualities required in many industrial applications. The electrodeposition of metals is one of the most common ways to add unique functional properties to metals and extra protection. This is why so many industries rely on electroplating to improve the durability, quality and performance of their components.
Aerospace
Electroplating is essential in aerospace, where components are exposed to extreme conditions. Nickel and silver plating provide wear and heat resistance, while gold plating is used on connectors for reliable conductivity. Precision coatings ensure aircraft parts maintain integrity and performance in flight-critical environments.
See Silver plating in the aerospace industry for more information.
Automotive
In the automotive sector, electroplating extends the lifespan of components subject to constant stress and corrosion. Zinc plating with passivates protects fasteners and brackets, while copper, nickel and chrome finishes enhance both performance and appearance. As the industry moves towards electrification, silver plating is also crucial for busbars and electrical connectors.
Read more in our article on The importance of electroplating for electric cars.
Data Centre
Today’s data centres need to be reliable and efficient; for this, they depend on the foundational role of electroplating. While it’s not always visible in daily operations, the integrity of servers, networking gear, and power distribution all depend on thousands of electroplated connectors, contacts, busbars, and circuit boards. Meticulous use of gold, silver, tin, and nickel coatings drives conductivity, resists corrosion, and guarantees dependable performance, even in high-heat, high-humidity environments.
Defence
Electroplating plays a vital role in the defence sector, where equipment must withstand extreme conditions. Coatings that combine durability, conductivity and corrosion resistance help ensure reliability in harsh environments, from land vehicles to naval and aerospace applications, where failure is not an option.
Electronics
Electroplating underpins the manufacture of components in the electronics sector, including printed circuit boards, connectors and contacts. Gold and silver provide low-resistance, high-reliability connections, while tin ensures excellent solderability. Without electroplating, modern electronics would not achieve the required performance or durability.
Electrical and Electrification
Electroplating plays a crucial role in the electrical sector, where reliable conductivity and corrosion resistance are essential. It is widely used on components such as busbars, switchgear and connectors, improving performance and reducing energy loss in power distribution systems. These coatings ensure safety, efficiency and long-term durability across critical infrastructure.
Medical
In the medical sector, electroplating enhances surgical instruments and implants. Gold and silver coatings provide biocompatibility and corrosion resistance, while precision plating ensures components meet strict hygiene and performance standards required in healthcare environments.
For more information, see our Resource pages:
Benefits of silver plating in the medical industry
The significance of gold plating in the medical industry
Rail and Transportation
Rail infrastructure relies on electroplated components to withstand outdoor exposure and heavy use. Zinc plating protects fasteners, while silver and copper coatings improve the conductivity of signalling and power systems. These measures extend asset lifespan and improve reliability across the network.
Further information: How electroplating gives rail components a new lease of life
Power Generation
In power generation, reliability is critical. Electroplating provides conductivity and corrosion resistance for turbine components, switchgear and connectors. Coatings reduce maintenance requirements and help ensure continuous operation in demanding conditions.
Telecommunications
Signal integrity and reliability in telecommunications systems depend on electroplated connectors and contacts. Gold and silver finishes provide high conductivity and resistance to wear, ensuring consistent performance in data transmission and networking equipment.
Read more: Busbar plating and its role in the communications industry
Oil & Gas
Suppliers and equipment manufacturers in the oil and gas sector rely heavily on electroplating to protect components, improve performance, and extend service life. Without proper surface finishing, parts can fail prematurely leading to higher operating costs, unplanned downtime, and even the risk of critical system failures.
The environments in which oil and gas equipment operates are among the harshest in any industry. Extreme temperatures, corrosive offshore conditions, and constant mechanical stress all place significant pressure on components. Our electroplating services help ensure these parts can withstand demanding conditions and continue performing reliably over time.
Take a look: Methods of Electroplating for the Oil and Gas Industry
Advantages of electroplating
Improved surface finish
Electroplating produces a smooth, uniform and often lustrous finish that enhances both function and appearance. This not only improves aesthetics for visible parts but also reduces tarnish, makes surfaces easier to clean, and ensures consistent performance in critical applications.
Electrical and thermal conductivity
Certain metals, including copper, silver and gold, are excellent conductors of electricity and heat. Applying these coatings through electroplating ensures efficient current transfer, reduced resistance and improved reliability. These are key requirements for industries such as electronics, telecommunications and power distribution.
Hardness and wear resistance
Metals such as nickel and silver provide coatings with high hardness and resistance to abrasion. By protecting the underlying component from friction and mechanical stress, electroplating extends service life, lowers replacement costs, and maintains performance even under demanding operating conditions.
Corrosion protection
Coatings such as Zinc, nickel and gold act as protective barriers against moisture, chemicals and environmental exposure. Zinc plating is particularly valued for its sacrificial properties as it corrodes preferentially, protecting the steel substrate beneath and preventing structural failure.
Dimensional restoration
Electroplating can restore worn or undersized parts by building up controlled layers of metal, returning them to their original specification. This reduces waste, lowers replacement costs, and extends the working life of valuable components across multiple industries.
Versatility
Electroplating plays a vital role in the defence sector, where equipment must withstand extreme conditions. Coatings that combine durability, conductivity and corrosion resistance help ensure reliability in harsh environments, from land vehicles to naval and aerospace applications, where failure is not an option.
OTHER BENEFITS
There are also many indirect benefits to electroplating, such as the ability for this process to be customised. In practical industrial applications, these benefits could look like:
Wide Range Of processes
Electroplating can be applied to a wide range of substrate metals, including aluminium, steel, copper, and alloys such as Inconel. This broad compatibility means companies across many industries can benefit from electroplating to improve the performance and durability of their components, without being limited to a specific base metal. While some other metal finishing processes, such as anodising, are mainly suited to particular metals like aluminium and titanium, electroplating offers far greater flexibility in substrate choice. This versatility makes it one of the most widely applicable finishing techniques available today.
Plating thickness
Plating thickness is usually measured in microns, reflecting the very thin nature of most electroplated coatings. Designers and engineers have the freedom to specify plating thickness to suit critical requirements, such as minimising weight and saving space with ultra-thin coatings, or meeting the plating requirements of heavy build plating. This flexibility ensures that both minimal and substantial plating thicknesses are possible, depending on component needs.
Visual
Electroplated finishes aren’t just functional, they can also be chosen for their appearance. Depending on the metal and process used, finishes can range from bright and reflective to satin, matt, or dull. Examples include bright tin, bright nickel, and dull nickel, each offering a distinct visual effect that meets different design and performance needs. This flexibility allows manufacturers to achieve the look, the technical performance required for their products and safety considerations like identification.
It’s one of the reasons electroplating is widely used across industries such as automotive, electronics and consumer goods, where the final appearance is just as important as durability and protection.
Repairs and refurbishment
In sectors like rail and transport, electroplating isn’t just used for new parts; it also plays a crucial role in repairing and refurbishing worn or damaged components. Our electroplating processes, particularly nickel and copper plating, are utilised to restore surfaces on machine shafts and other critical components that have suffered wear in service, returning them to their original dimensions and performance levels. This method gives components a new lease of life without the need for costly replacements. It’s a proven way to reduce waste, cut carbon emissions, and lower demand for new raw materials, key goals in achieving a more sustainable, circular economy. For transport and rail operators, refurbishment through electroplating also supports cost control and helps keep fleets running efficiently, allowing budgets to be reinvested in other areas. For more information, see our article The Benefits of Electroplating.
Limitations and environmental considerations
Process control
Electroplating is a precise science. High-quality results depend on maintaining strict control of bath chemistry, current density, temperature and plating time. Even small variations can lead to uneven deposits, poor adhesion or reduced performance. Careful monitoring and process management are therefore essential to guarantee consistent outcomes.
Surface-only protection
Electroplating enhances only the surface of a component. If a coating is scratched, worn away or otherwise damaged, the underlying substrate can be exposed to corrosion or wear. Choosing the right plating metal, applying sufficient thickness and, where necessary, using multi-layer systems helps mitigate this limitation and maintain long-term performance.
Production time
The time required for electroplating depends on the coating thickness and the size of the component. Thin functional layers can be deposited quickly, but thicker or multi-metal coatings require longer cycles. Production schedules must balance efficiency with the durability required for the end application.
Environmental and regulatory compliance
Electroplating involves the use of chemicals that are strictly regulated under UK and EU law. Responsible handling, treatment and disposal are essential to minimise environmental impact.
As a UK-based provider, Karas holds an Environmental Permit and operates under REACH and RoHS directives. Accreditation to ISO 14001 Environmental Management further demonstrates our commitment to sustainable practices and compliance with regulatory requirements.
Hydrogen Embrittlement
Hydrogen embrittlement is a risk, particularly in high-strength steels and certain alloys. During plating, hydrogen is generated at the cathode (the component being plated), and some atoms can diffuse into the metal. If unmanaged, this can make the material brittle and more susceptible to cracking under stress—especially in critical components such as fasteners, springs, and aerospace or automotive parts.
Without proper control, hydrogen embrittlement can lead to unexpected component failure, raising concerns about safety, reliability, and warranty. However, within the plating industry, this is a well-understood and fully manageable challenge.
We apply proven process adaptations to minimise and eliminate hydrogen embrittlement risks:
Post-plating bake-out (de-embrittlement baking): Heating the plated part shortly after processing removes absorbed hydrogen before it can cause damage.
- Careful management of pre-treatments (like acid pickling), electrolyte chemistry, and plating parameters reduces hydrogen uptake at every stage.
Hydrogen embrittlement is a known factor, not a barrier to high-quality electroplating. With the right techniques and process control, the benefits of electroplating, like corrosion protection, conductivity, and appearance, far outweigh the risks.
Our technical team can advise on tailored solutions for high-strength materials or safety-critical components, helping you achieve reliable, high-performance plating results with complete confidence.
Future Developments in Electroplating
Electroplating is a well-established process, but it continues to evolve to meet the needs of modern industry. Research and development are driving improvements in efficiency, sustainability and precision. Advances in bath chemistry, process monitoring and automation are enabling manufacturers to achieve more consistent results while reducing waste and energy use.
Karas has also invested in the future of electroplating. Alongside a fully automated silver plating line for copper busbars, the company has recently installed an additional automated silver plating line and a brand-new metal preparation area. These facilities strengthen capacity, improve repeatability and demonstrate a clear commitment to continuous improvement.
For customers, these developments translate into reliable coatings, faster turnaround times and the assurance that every project is supported by the latest technology and best practice.
See our News page for the latest developments in equipment, processes and capacity.
Frequently asked questions
What materials can be electroplated?
Most conductive metals can be electroplated, including steel, copper, brass and aluminium (with appropriate pre-treatment). The choice of base material often determines which plating process or undercoat is required.
Why can’t all metals be plated directly onto any substrate?
Some metals do not adhere well together. An intermediate layer, such as copper or nickel, may be used to ensure compatibility.
How is consistency guaranteed across large production runs?
Through strict process control, advanced monitoring and automated equipment where appropriate. This ensures that every component within a batch meets the same specification for thickness, adhesion and finish.
How is plating thickness controlled?
By adjusting current density, bath composition and plating time. Karas uses advanced monitoring to achieve precise specifications.
Does electroplating wear off?
Over time, electroplated coatings can wear down due to friction, abrasion or exposure to harsh environments. The lifespan of a plated finish depends on factors such as the thickness of the coating, the metal used, and the conditions in which the component operates. With the right plating specification, coatings can last for many years and significantly extend the service life of the base component.
How long does electroplating take?
Turnaround depends on coating thickness, component size and production volume. Thin layers can be deposited quickly, while thicker coatings require longer cycles. Automated lines help maintain efficiency.
Can damaged coatings be repaired?
Yes. Localised techniques such as brush plating can restore worn or damaged areas without reprocessing the entire component.
Why choose Karas for electroplating?
Karas has been delivering specialist electroplating services for over 50 years, combining technical expertise with a commitment to quality and sustainability.
- Comprehensive expertise – We offer copper, zinc, tin, nickel, silver and gold plating, enabling solutions tailored to both decorative and demanding engineering applications.
- A range of plating lines – automated for high volume parts and ultra-wide lines up to 4.2metres, perfect for longer components
- Proven quality standards – Karas is accredited to ISO 9001, ISO 14001 and ISO 45001, ensuring consistent quality, environmental responsibility and occupational safety.
- Regulatory compliance – We operate under a formal Environmental Permit and maintain full REACH and RoHS compliance.
- Logistics – Quick turnaround & nationwide collection/delivery.
- Quality Equipment – We use high-quality equipment, including plating baths built to withstand corrosion and chemical attack from chemical solutions. Additional technology includes X-ray machines and XRF analysers for reliable checks on coating thickness and composition.
- Technical capability – Our facilities include high-capacity plating lines and an automated silver electroplating line for busbars, giving us the ability to handle both complex one-off projects and high-volume production.
- Industry knowledge – We serve clients in automotive, aerospace, rail, medical, defence and electronics, with sector-specific expertise.
- Customer focus – From prototyping and testing to full-scale production, Karas provides advice, flexibility and responsive service to ensure every project meets its objectives.
Partner with Karas Plating
Karas Plating combines decades of expertise with strict quality and environmental standards to deliver reliable, high-performance finishes.
Contact our expert team today for tailored advice, precision finishes, and full compliance with industry standards. We’ll help you find the right solution for your components and applications.