Metal fasteners are often exposed to moisture, chemicals, and changing temperatures. Without protection, they can corrode quickly and then fail. Applying an effective coating improves corrosion resistance and performance. Several coating options are common, each will have their own different benefits depending on the application and environment.
1.Chemical Black
Chemical black is a surface treatment rather than a thick coating. It creates a thin black layer through a chemical reaction with the metal surface. This finish provides only a little corrosion resistance on its own, so it is usually combined with oil or wax.
2. Black Oxide
Black oxide is similar to chemical black but provides slightly better durability because it forms a controlled oxide layer that improves resistance and offers a little corrosion protection when sealed. Black oxide is commonly used for applications indoors or in environments with low corrosion.
3. Electro Zinc Plating
Electro nickel plating, such as https://www.poeton.co.uk/surface-treatments/plating/zinc-nickel-plating/, is widely used for fasteners due to its affordability and good resistance to corrosion. A thin zinc layer is applied using an electrical current. This coating provides sacrificial protection, meaning the zinc corrodes before the steel. In some cases, zinc nickel plating is preferred for higher resistance to corrosion and improved heat performance.
4. Iso Fit Galvanise
Iso Fit galvanising applies a thicker zinc coating designed to fit threaded fasteners accurately. It provides excellent corrosion resistance, even in industrial conditions. The coating forms a protective patina over time, extending the service life of the metal. Iso Fit galvanisation is often chosen for structural and heavy-duty applications where durability is needed.
