Also known as sherardizing, mechanical zinc plating is a metal treatment widely used in industry, especially to strengthen very small parts such as screws, nails and washers. As the name suggests, it is a mechanical process that coats the metal with a layer of zinc, making it more resistant to impacts, damage and corrosion.
How is mechanical zinc plating done?
Let’s explain it in a few simple steps. As mentioned, zinc plating is used mainly for very small metal parts: these are loaded into a machine and tumbled inside a rotating drum at high temperature.
The machine used for zinc plating looks a lot like a cement mixer, with an internal temperature of between 300 and 400 °C. Zinc powder is added inside this “mixer” and settles on the parts, creating the layer we mentioned, which makes the metal sturdier and more resistant. The thickness of the coating varies according to requirements: as you would expect, the thicker the zinc layer, the more resistant the coating. There are usually three levels of coverage: 5–10 micrometres, 10–30 micrometres, and more than 30 micrometres.
Whatever level you need, mechanical zinc plating is always worth considering if you want a material to last longer.