Low, Mid or High Phosphorus Electroless Nickel: How to Choose the Right Spec
“Electroless nickel per AMS 2404” is one of the most common notes we see on aerospace prints. It is also one of the least specific. Electroless nickel (EN) is not a single coating. It is a nickel-phosphorus alloy, and the amount of phosphorus in the deposit changes how hard it is, how well it resists corrosion, whether it is magnetic, and how it behaves after heat treatment. If you are an engineer writing a specification or a buyer sending parts out for plating, knowing the difference between low, mid and high phosphorus EN helps you get the part you actually need, the first time. What “Phosphorus Content” Means Electroless nickel is deposited by a chemical reaction rather than electric current, usually with sodium hypophosphite as the catalyst. The reaction co-deposits phosphorus with the nickel, so the finished coating is an alloy. The plating chemistry controls how much phosphorus ends up Read more












