Select Page

AMS 2404

by | May 28, 2024

Key Takeaways:

  • Consistency and Quality Assurance: AMS 2404 ensures uniform electroless nickel plating, providing consistent results across intricate geometries and production batches, enhancing component reliability and performance. 
  • Enhanced Protection and Durability: Adhering to AMS 2404 offers superior corrosion and wear resistance, significantly extending the lifespan of components by protecting against environmental and operational stresses. 
  • Versatility and Design Flexibility: AMS 2404’s broad compatibility with various metals, such as steel, aluminum, and copper alloys, allows it to be applied across multiple industries, expanding design possibilities and ensuring high performance.


Electroless nickel plating offers a well-established method for depositing a thin nickel layer onto various metal surfaces. This process, achieved through a chemical reaction without electricity, provides numerous benefits for component performance and longevity. However, achieving consistent and reliable results requires adherence to a defined standard.

The Aerospace Material Specification (AMS) 2404 is a critical industry standard for electroless nickel plating. Developed and maintained by SAE International, it outlines the specific requirements for plating processes, ensuring consistent quality and performance across various applications.

In this article, we will discuss the key elements of AMS 2404, its applications, and its importance in maintaining the integrity and reliability of nickel-plated parts in various industries.

At Valence Surface Technologies, we rigorously follow AMS 2404 specifications to provide surface finishing solutions that meet the exacting standards of the aerospace industry. As we strive to be the most trusted partner in aerospace surface finishing, our adherence to such stringent standards underlines our commitment to quality and excellence.


What Is AMS 2404?

AMS 2404 is a crucial industry standard established by SAE International specifically for electroless nickel plating. This standard provides detailed guidelines for achieving consistent and high-performance results in this metal coating process. Unlike traditional electroplating, which uses electricity, electroless nickel plating relies on a chemical reaction to deposit a thin nickel layer onto a metal surface. 


Key Features Of AMS 2404 Plating

AMS 2404 plating boasts several key features that contribute to its widespread adoption and success:

Here’s a more professional take on the key features of AMS 2404 plating:


  • Uniform Deposition: AMS 2404 guarantees exceptional uniformity in the thickness of the electroless nickel layer. This consistent plating, even on intricate geometries, ensures predictable performance and optimal functionality across the entire component surface. 
  • Superior Corrosion Protection: The electroless nickel deposit acts as a highly effective barrier, significantly enhancing the underlying metal’s resistance to environmental degradation. This includes protection from moisture, chemicals, and other corrosive elements, ultimately extending the component’s service life. 
  • Elevated Wear Resistance: AMS 2404 plating delivers a demonstrably hard and wear-resistant surface. This minimizes abrasion and friction during operation, leading to extended component lifespan and reduced maintenance needs. 
  • Broad Material Compatibility: This established standard exhibits versatility by applying to a wide range of metallic substrates, including steel, aluminum, and copper alloys, allowing for its utilization across diverse applications in various industries.


Importance Of AMS 2404

The importance of AMS 2404 lies in its ability to ensure consistent and high-performance electroless nickel plating. Here’s a breakdown of its significance:


Guaranteed Quality and Repeatability

By adhering to the strict guidelines of AMS 2404, manufacturers can be confident that the electroless nickel plating process will be consistent across batches and production runs. This ensures predictable results and eliminates the risk of inconsistencies that could compromise component performance.


Enhanced Performance of Plated Components

AMS 2404 dictates parameters that lead to key benefits like:

  • Superior Corrosion Resistance: The nickel layer protects the underlying metal from environmental degradation, extending its lifespan and functionality.
  • Improved Wear Resistance: The plating provides a hard and wear-resistant surface, reducing wear and tear during operation and minimizing maintenance and downtime.
  • Uniformity Across Geometries: Consistent plating thickness, even on complex shapes, ensures predictable performance across the entire component.


Broader Design Flexibility

The versatility of AMS 2404 allows its application on various metals, such as steel, aluminum, and copper alloys. This expands engineers’ design possibilities, enabling them to incorporate the benefits of electroless nickel plating across a wider range of components and industries.


Reduced Risk and Increased Reliability

AMS 2404 minimizes the risk of component failures caused by inconsistent plating quality by guaranteeing a standardized and controlled plating process. This translates to increased reliability and safety in applications where performance is critical.


In essence, AMS 2404 is a cornerstone for achieving high-performance and reliable electroless nickel plating, ultimately contributing to the extended lifespan, enhanced functionality, and overall success of components across various industries.


Preparation And Pre-Treatment In AMS 2404

The meticulous preparation and pretreatment of the parts to be plated are critical to achieving the high-quality results demanded by this standard. This stage is crucial because it significantly affects the final coating’s adhesion, structure, and durability.


Cleaning and Degreasing

Before any plating can begin, it is essential to thoroughly clean and degrease the substrate. This step removes contaminants such as oils, greases, and other surface residues that could interfere with the plating process.

Typically, the cleaning process involves a series of chemical and mechanical treatments designed to prepare the surface for optimal coating adhesion. Techniques such as alkaline, ultrasonic, and acid etching are frequently employed.


Cleaning and Degreasing


Surface Activation

Once the substrate is cleaned, it undergoes a surface activation to ensure the electroless plating adheres properly. This involves treating the surface with specific chemical solutions that enhance its chemical properties, creating an ideal base for the electroless nickel to deposit. Surface activation is critical for materials like aluminum alloys, which naturally form a passive oxide layer that can inhibit plating.



After each pre-treatment step, thorough rinsing is required to remove any residual chemicals left on the substrate. This step is vital to prevent unwanted reactions during electroless nickel plating. The quality of the water used for rinsing—often deionized—is crucial to avoid introducing new contaminants to the cleaned and activated surface.


Pre-Plating Inspection

Substrates should thoroughly inspect before plating begins to ensure they meet the specified cleanliness and surface condition requirements. Any defects or irregularities should be addressed before proceeding with plating.


Compatibility Testing

Depending on the substrate material and the plating process used, compatibility testing may be necessary to ensure the substrate can withstand the plating process without degradation or adverse effects.


AMS 2404 Procedure: Achieving Consistent Electroless Nickel Plating

After the preparation and pre-treatment, the electroless nickel plating process unfolds in these key steps:



  • The cleaned and prepared component is submerged in an activation solution for a short duration.
  • This solution typically contains mild acids or salts that activate the metal surface, promoting a strong bond with the electroless nickel deposit.


Electroless Nickel Plating

The activated component is immersed in a plating bath containing a complex solution of:

  • Nickel ions: These are the source of the nickel metal that will be deposited on the component’s surface.
  • Reducing agent: This chemical triggers the electroless reaction that deposits nickel ions from the solution onto the activated surface. Common reducing agents include sodium hypophosphite or boron hydrides.
  • Buffering agents: These maintain a stable pH level within the plating bath, ensuring optimal reaction conditions.
  • Complexing agents: These control the rate of nickel deposition and influence the plating’s final properties (e.g., hardness, and phosphorus content).

The plating bath is usually maintained at a specific temperature range as defined by the plater and the desired properties of the nickel deposit.

The duration of immersion in the plating bath determines the final thickness of the nickel layer. AMS 2404 typically specifies a range of acceptable thickness based on the application.


Rinsing and Drying

  • Once the desired plating thickness is achieved, the component is removed from the bath and thoroughly rinsed with clean water.
  • This rinsing step removes any residual plating solution that may be present on the surface.
  • The plated component is then carefully dried to prevent contamination or oxidation.


Post-Treatment (Optional)

Depending on the specific application and desired properties of the final product, the plated component may undergo additional post-treatment processes:

  • Heat Treatment: As defined by the AMS 2404 class (1-4), the component may be subjected to a controlled heat treatment process. This can improve the hardness of the nickel deposit, enhance adhesion for specific substrates like aluminum alloys, or relieve hydrogen embrittlement that can occur during plating.
  • Surface Finishing: Optional processes like polishing or buffing may be used to achieve a desired surface finish or improve specific characteristics like reflectivity or wear resistance.


Applications Of AMS 2404 In Industry

AMS 2404 finds wide-ranging applications across various industries where the quality and performance of nickel-plated components are essential. Some key industries where AMS 2404 is commonly applied include:


Aerospace Industry

Component reliability and performance are paramount in the aerospace industry. AMS 2404 electroless nickel plating is extensively utilized for parts like gears, shafts, and bearings in aircraft engines. This plating helps enhance the wear resistance and corrosion protection of these components, which are regularly exposed to harsh environments and high temperatures.


Defense Sector

The defense sector benefits significantly from AMS 2404, which enhances the lifespan and durability of military equipment. Components treated with electroless nickel plating, as specified by AMS 2404, are found in various applications, ranging from firearms and optical devices to vehicle components and aerospace defense systems.

This treatment ensures these components can withstand extreme conditions and perform consistently in critical situations.


Space Exploration

Satellites and vehicles must operate in extreme vacuum conditions and varying thermal ranges in space exploration. Components coated with AMS 2404 electroless nickel plating guarantee a high level of protection against corrosion, wear, and radiation, ensuring the longevity and reliability of spacecraft parts, which are crucial for successful missions.


 Space Exploration


Finding Qualified AMS 2404 Plating Services

Finding qualified AMS 2404 plating services is essential to ensure that your nickel-plated components meet your industry’s stringent quality and performance standards. Here are some steps to find reputable AMS 2404 plating services:


  • Accreditation Matters: Look for NADCAP or industry association certification, verifying the plater’s commitment to quality and AMS 2404 adherence. 
  • Experience is Key: Choose a plater experienced with AMS 2404 and your specific application, including expertise in component types, plating thicknesses, and post-treatment options. 
  • Quality Control is Crucial: Ensure the plater has robust quality control procedures, including bath chemistry monitoring, plating thickness verification, and documented AMS 2404 compliance processes. 
  • Verify Credentials: Request documentation of the plater’s AMS 2404 certification and quality control procedures. 
  • Balance Needs & Costs: Consider turnaround time, pricing, value-added services, and the importance of quality and AMS 2404 adherence.

At Valence Surface Technologies, we pride ourselves on meeting these high standards. Our certification signifies our commitment to providing top-tier surface treatments that enhance aerospace components’ durability, performance, and longevity. With a robust track record of serving the aviation, defense, and space sectors, Valence ensures that every element we treat is done with the utmost precision and care.


Check out these additional articles for more insights.


Frequently Asked Questions

What documentation is required under AMS 2404?

Documentation typically includes process certifications, quality assurance records, and inspection reports for AMS 2404 compliance. This ensures traceability and verification that the electroless nickel plating meets aerospace standards.


Are there environmental considerations in AMS 2404?

Yes, AMS 2404 includes environmental considerations, focusing on waste management and using non-toxic chemicals where possible. Compliance with environmental regulations is essential to minimize the impact of the electroless nickel plating process.


What safety protocols are recommended in AMS 2404?

Safety protocols in AMS 2404 recommend proper ventilation, personal protective equipment (PPE), and training for handling chemicals. Regular audits and compliance with OSHA guidelines are crucial to ensure a safe working environment.


Can AMS 2404 be applied to non-metal substrates?

AMS 2404 is specifically designed for metal substrates. Application on non-metal substrates requires different surface preparation and adhesion processes, which are not covered under AMS 2404 standards.


What are the common challenges in meeting AMS 2404 standards?

Challenges in meeting AMS 2404 standards include maintaining consistent thickness and uniformity of the nickel plating, adhering to strict chemical composition requirements, and ensuring proper adhesion and corrosion resistance.


How does AMS 2404 impact manufacturing costs?

While AMS 2404 can increase upfront manufacturing costs due to stringent quality and compliance requirements, it often leads to longer component lifespan and reduced maintenance costs, ultimately providing better value in aerospace applications.


How can I find a qualified AMS 2404 plating service provider?

To find a qualified AMS 2404 plating service provider, look for certifications and accreditations specific to aerospace industry standards. Providers like Valence Surface Technologies are equipped to meet these rigorous requirements and offer comprehensive solutions.


What are some alternatives to AMS 2404 plating?

Alternatives to AMS 2404 plating include different types of electroplating, such as zinc or cadmium plating, and physical vapor deposition (PVD) processes, depending on the specific application and performance requirements.


How does AMS 2404 compare to other electroless nickel plating processes?

AMS 2404 is highly regarded for its stringent quality controls and aerospace-specific requirements. It generally offers better corrosion and wear resistance than standard electroless nickel plating processes, making it ideal for aerospace applications.


Does AMS 2404 affect the electrical conductivity of a component?

AMS 2404 may slightly alter a component’s electrical conductivity, as the nickel plating adds a non-conductive layer. The impact depends on the thickness and specific properties of the nickel deposit.

Our expertise and processes make doing business easy.