What thickness should I use for …?
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 corrosion resistance of the zinc depends on two things:
- zinc thickness — this protects the base material from corrosion (often referred to as protection to “red rust”)
- passivation — this protects the zinc from corrosion (often referred to as protection to “white rust”)
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.
|Environmental Conditions||Wear/Abrasion Conditions||Examples||Suggested (Minimum) Thickness||ISO 2081 Designation|
|Dry, clean, indoor||Minimal||Offices, domestic premises (excluding kitchens and bathrooms)||5µm||Zinc plate and clear passivate Fe/Zn5/A|
|Clean, indoor, minimal condensation||Minimal||Warehouses, light assembly workshops||8µm||Zinc plate and clear passivate Fe/Zn8/A|
|Indoors or covered outdoors||Some||Light industry (excluding exposure to corrosive substances), in domestic garden areas covered by roofs.||12µm||Zinc plate and clear passivate Fe/Zn12/A|
|Outdoors||Some, risk of scratching or denting||Industry (with limited exposure to corrosive substances), marine environments (not immersed, not splashed), outdoors.||25µm||Zinc plate and clear passivate Fe/Zn25/A|
In the most corrosive environments, particularly those with a risk of salt spray, zinc plating alone will probably be insufficient. It is suggested that you have the part zinc plated and then paint any exposed areas. We do not recommend powder coating.
For some applications, designers may opt to use zinc-nickel plating instead of zinc plating for further corrosion resistance, the above table will not be applicable.
Your Purchase Order
Please tell us what thickness you require on your purchase order. We suggest that you specify using the ISO 2081 system (as in table above).
More Info and Specialist Advice
Please email us if you would like advice on zinc plating thickness. This page just gives general suggestions and our specialists will be able to provide more in-depth information.
This page is provided for information only, it should not be considered advice and we cannot accept any responsibility or liability for your use of the information on this page. The information on this page is used and relied on at your own risk and you bear the sole responsibility for any outcomes. E&OE.