The thickness of zinc plating that you should use depends on the environment that the component is in. We have produced some recommendations based on what we find is suitable for most of our customers.
The protection from the zinc plating is proportional to the thickness of the zinc plating - so thicker zinc means more protection for the base metal. Thickness has almost no effect on the resistance to "white rust" because this involves the coating itself corroding.
Usually, according to actual environment we can choose from:
1. Dry, clean, indoor - 5µm
2.Clean, indoor, minimal condensation - 8µm
3. Indoors or covered outdoors - 12µm
4.Outdoors - 25µm or more
Here is an example we test coating thickness before shipment.
With 125um thickness, the finish can last for even 50 years. It is suitable for public facilities.
And for the appearance:
Zinc coatings can be applied in many different colors with or without brilliant finishes. Zinc plating is available in yellow/gold, clear/blue, black and green, with the addition of topcoats known as "Chromates." These topcoats can add many more hours of salt spray corrosion protection on the zinc-plated product.
If you still don't know how to choose a finish for your metal piece, contact Starway group for suggestions!