Electroplating
Electrolytic deposition of metal coatings (nickel, chrome, zinc, gold) for enhanced conductivity, corrosion resistance, and decorative appearance. All processes are RoHS compliant.
About Electroplating
Electroplating is an electrolytic process that deposits a thin layer of metal onto a conductive substrate to enhance its surface properties. By immersing the part in a solution containing dissolved metal ions and applying an electrical current, a uniform metallic coating is built up atom by atom on the workpiece surface. This process allows engineers to combine the structural properties of one metal with the surface properties of another, optimizing cost, weight, and performance.
Electroplating is essential across numerous industries. In electronics, gold and silver plating provide reliable electrical contacts and connectors. In automotive and consumer products, chrome and nickel plating deliver a brilliant, corrosion-resistant decorative finish. In industrial applications, zinc plating protects steel fasteners and structural components from rust, while nickel plating provides wear resistance and solderability. All FabRapid electroplating processes are RoHS compliant, using trivalent chromium and non-cyanide chemistries where applicable.
The choice of plating metal depends on the application requirements. Gold offers the best electrical conductivity and corrosion resistance for electronic contacts. Chrome provides the hardest, most wear-resistant decorative finish. Nickel offers an excellent balance of corrosion resistance, hardness, and solderability. Zinc is the most economical option for sacrificial corrosion protection of steel components. Multi-layer plating systems (such as copper-nickel-chrome) are available for demanding applications requiring the combined benefits of multiple metals.
Finish Properties
Available Types
Nickel Plating
Versatile plating with excellent corrosion resistance, moderate hardness (200-700 HV depending on formulation), and good solderability. Available in bright (mirror-like), semi-bright, and electroless (uniform thickness) variants. Widely used for engineering components, electronics, and as an undercoat for chrome plating.
5-40 µm
Chrome Plating
Hard, brilliant finish with exceptional wear resistance and low friction coefficient. Decorative chrome (0.25-0.5 µm) is applied over nickel for a mirror-bright appearance. Hard chrome (25-250 µm) is applied directly for industrial wear resistance on hydraulic rods, mold surfaces, and cutting tools.
0.25-250 µm
Zinc Plating
Cost-effective sacrificial corrosion protection for steel and iron parts. Zinc corrodes preferentially, protecting the base metal even when the coating is scratched. Available with chromate, trivalent passivation, or clear sealant for enhanced protection. Standard for fasteners, brackets, and automotive stampings.
5-25 µm
Gold Plating
Premium plating with the highest electrical conductivity and corrosion resistance. Used primarily for electronic connectors, contacts, and PCB pads where reliable signal transmission is critical. Also used for medical implants and decorative luxury applications. Typically applied as a thin flash (0.1-0.5 µm) over nickel undercoat to minimize cost.
0.1-5 µm
How It Works
Electroplating begins with thorough surface preparation: cleaning, degreasing, acid activation, and optional strike plating to ensure adhesion. The prepared part is immersed in an electrolyte solution containing dissolved ions of the plating metal (e.g., nickel sulfate for nickel plating, zinc chloride for zinc plating). The part serves as the cathode (negative electrode), and a piece of the plating metal or an inert anode serves as the anode (positive electrode). When direct current is applied, metal ions in the solution are reduced and deposited onto the part surface. The coating thickness is controlled by current density, bath temperature, and plating time. After plating, parts are rinsed, dried, and may receive post-treatments such as chromate passivation (for zinc) or heat treatment (for hydrogen embrittlement relief on high-strength steels).
Design Guidelines for Electroplating
Account for plating buildup in tolerance calculations—electroplating adds material uniformly, so a 25 µm nickel plate adds 25 µm per side to all external dimensions and reduces bore diameters by 50 µm.
Avoid sharp internal corners and deep recesses where current density is low—plating thickness drops significantly in recessed areas (Faraday cage effect), so use radii of at least 1 mm on internal edges.
Specify hydrogen embrittlement relief baking (190°C for 4+ hours) for high-strength steel parts (>1000 MPa / 40 HRC) that are zinc or cadmium plated to prevent delayed brittle fracture.
Design rack points or hanging features for electrical contact—at least one surface will have contact marks from the plating fixture that cannot be plated.
For multi-layer plating (e.g., copper-nickel-chrome), specify each layer thickness individually to ensure proper adhesion and performance of the complete system.
Compatible Materials
Materials that can be finished with electroplating.
Electroplating FAQ
Electroplating uses electrical current to deposit metal, producing coatings that are thicker on edges and thinner in recesses due to current distribution. Electroless plating uses a chemical reduction reaction (no external current), producing perfectly uniform thickness on all surfaces regardless of geometry. Electroless nickel plating is preferred for complex geometries requiring uniform coverage, while electroplating is more economical for simple shapes and allows a wider range of plating metals.
Aluminum cannot be directly electroplated due to its tenacious oxide layer, which prevents adhesion. A zincate pretreatment process (immersion in alkaline zinc solution) is required to dissolve the oxide and deposit a thin zinc layer that provides a platable surface. This zinc strike is then overplated with copper, nickel, or the desired final metal. Without proper zincate pretreatment, the plating will peel off the aluminum substrate.
Hydrogen embrittlement occurs when atomic hydrogen, generated during the plating process, diffuses into high-strength steel and causes delayed brittle fracture under load. Parts with hardness above 40 HRC (approximately 1000 MPa tensile strength) are at risk, particularly fasteners, springs, and landing gear components. The standard mitigation is a post-plating bake at 190°C for 4-23 hours to drive out absorbed hydrogen before the parts are placed in service.
Zinc plating provides sacrificial protection—it corrodes preferentially to protect the steel substrate, making it ideal for fasteners and structural components that may be scratched in service. Nickel plating provides barrier protection—it is harder and more corrosion-resistant than zinc but will not protect the substrate if the coating is breached. Choose zinc for cost-effective, sacrificial protection of steel, and nickel when hardness, solderability, or decorative appearance are also required.
All FabRapid electroplating processes are RoHS compliant. We use trivalent chromium (Cr3+) passivations instead of hexavalent chromium (Cr6+) for zinc plating, and non-cyanide electrolytes for gold and silver plating. Cadmium plating is not offered. Our nickel and chrome plating processes comply with REACH and RoHS directives. Certificates of compliance are available upon request for all plating processes.
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