Electroless plating

The Pros and Cons of Electroless Plating in CNC Machining

cnc machined parts with electroless plating finish

Electroless plating is a type of chemical plating process that is commonly used in the manufacturing industry. It is a process in which a metal substrate is coated with a thin layer of another metal or alloy without the need for an external electrical power source. Unlike electroplating, which requires an external power source to initiate the plating process, electroless plating relies on a chemical reaction between the substrate and the plating solution.

Electroless plating is often used in CNC machining to achieve a high-quality surface finish on metal parts. This process is particularly useful for parts with complex geometries or internal cavities that are difficult to coat using traditional electroplating methods. By using electroless plating, manufacturers can produce parts with a uniform coating thickness and excellent corrosion resistance.

In CNC machining, electroless plating can be used to produce a variety of coatings, including nickel, copper, gold, and silver. Each coating offers different properties and benefits, depending on the application. For example, nickel coatings are often used to improve wear resistance, while copper coatings are used for electrical conductivity.

Overall, electroless plating is a versatile and effective method for producing high-quality metal surface finish coatings in CNC machining. Its ability to coat complex geometries and internal cavities makes it a popular choice for a wide range of manufacturing applications.

Pro & Cons


  1. Uniformity: Electroless plating provides a uniform coating thickness over complex shapes and internal surfaces, making it a popular choice for parts with intricate geometries.
  2. Corrosion resistance: Electroless plating produces a corrosion-resistant surface, which can increase the longevity and durability of the part.
  3. Consistency: Because electroless plating relies on a chemical reaction rather than an external electrical power source, it can produce consistent results from one part to the next.
  4. Lower cost: Electroless plating can be a lower-cost alternative to other plating methods that require more specialized equipment and processes.
  5. No electrical connection required: Unlike electroplating, which requires an electrical connection to the part being plated, electroless plating does not require an electrical connection, making it safer and easier to use.


  1. Limited material choices: Electroless plating is typically limited to a few materials, such as nickel, copper, and gold.
  2. Limited thickness control: Electroless plating can produce a uniform coating thickness, but it can be difficult to control the thickness precisely.
  3. Limited control over surface finish: Electroless plating can produce a smooth surface finish, but it may not be as controllable as other surface finishing methods.
  4. Limited adhesion: Electroless plating may not adhere as well to certain materials, which can affect the overall quality of the coating.
  5. Limited scalability: Electroless plating may not be as scalable as other plating methods, which can make it more difficult to use for large-scale manufacturing operations.

Design Tips

  1. Material selection: The material of the part can affect the adhesion and quality of the electroless plating. It is important to choose a material that is compatible with the plating process and can achieve the desired surface finish.
  2. Surface finish requirements: The desired surface finish should be specified in the design, including the roughness and flatness requirements. This will help ensure that the part can be machined to the correct specifications and that the plating will adhere properly.
  3. Geometry: The geometry of the part can affect the plating process, particularly for complex shapes or parts with internal cavities. Designers should consider the accessibility of the surfaces to be plated and the thickness of the plating required.
  4. Tolerance requirements: Tolerance requirements should be taken into account during the design process to ensure that the part can be machined to the required specifications and that the plating will not affect the part’s dimensional accuracy.
  5. Cost considerations: The cost of electroless plating can vary depending on the material, thickness, and other factors. Designers should consider the cost of the plating process when designing the part to ensure that it is cost-effective and fits within the overall budget.


What is the difference between electroplating and electroless plating?

Electroplating and electroless plating are both methods of adding a metal coating to a substrate, but they differ in their mechanism of deposition. Electroplating involves the use of an external electrical power source to deposit the metal coating onto the substrate, while electroless plating relies on a chemical reaction to initiate the deposition process. Electroless plating does not require an external electrical connection to the substrate and can be used to coat complex geometries and internal surfaces that are difficult to coat using electroplating.

What is the correct process of electroless plating?

The process of electroless plating typically involves the following steps:

a) Cleaning and pretreatment: The substrate is cleaned and pretreated to remove any contaminants and prepare the surface for plating.

b) Activation: The substrate is activated with a solution to provide a surface for the plating to adhere to.

c) Immersion: The substrate is immersed in an electroless plating solution that contains the metal ions to be deposited.

d) Deposition: The metal ions in the plating solution react with the substrate and reduce to form a thin layer of metal coating on the surface.

e) Post-treatment: The plated part is rinsed and post-treated to improve adhesion and corrosion resistance.

What metals can be electroless plated?

A variety of metals can be electroless plated, including nickel, copper, gold, silver, palladium, and platinum. The choice of metal depends on the desired properties of the plated part, such as wear resistance, electrical conductivity, or corrosion resistance. Some non-metallic substrates, such as plastics and ceramics, can also be electroless plated with certain metal coatings.


You’re one step from the  factory-direct price of part manufacturing services.