How to Calculate the Coating Thickness of Galvanized Steel Plate?
As specialists in all things hot-dip galvanizing, our team at Ruisite can provide expert guidance on the best galvanized materials to use for your projects.
Author: Robby
As a common anti-corrosion material, galvanised steel sheet has a wide range of applications in construction, home appliances, automotive and other industries. So how to calculate the galvanised thickness of galvanised steel sheet?
Firstly, we need to understand what is coating thickness. Coating thickness is the thickness of the surface coating of galvanised steel. Typically, the thickness of galvanising is expressed in terms of coating thickness and is measured in μm (microns).
What Makes Some Hot-Dip Galvanized Materials Thicker?
Several factors influence the thickness of a zinc coating, with the most significant being the material itself. The thickness and chemical composition of the original steel play a crucial role in determining the final coating thickness. Steel with a higher silicon content and greater thickness tends to develop a thicker zinc coating during the galvanizing process. Under standard hot-dip galvanizing procedures, the steel naturally achieves a coating that meets the minimum required thickness without additional intervention.
For projects requiring a thicker zinc coating, specific measures can be taken after hot-dip galvanizing. It is essential to consult with the galvanizing service provider beforehand to discuss project requirements. If an exceptionally thick coating is needed, selecting the appropriate raw materials can help achieve the desired results.
For example, the ASTM A123 specification standard range for hot-dip galvanizing is 1.4 to 3.9 mils. As long as the thickness is in that range, then your material will have the best corrosion protection. As specialists in all things hot-dip galvanizing, our team at South Atlantic Galvanizing can provide expert guidance on the best galvanized materials to use for your projects.
So how do you calculate galvanising thickness? Generally, the thickness of the coating is calculated from the weight ratio of the metal substrate to the zinc coating. The exact calculation formula is as follows:
Galvanised thickness (μm) = weight of zinc coating (g/m²) ÷ 7.14
Where 7.14 is the specific gravity of zinc. In other words, the weight of the zinc layer divided by 7.14 is the galvanising thickness.
How Thick Is Galvanized Coating?
In practice, we usually come across some common plating thickness requirements. For example:
1. general galvanising thickness should be 45μm or more.
2. parts in contact with foodstuffs in the food industry should have a thickness of 80 μm or more.
3. parts used in the automotive, refrigeration, and ice-making industries should be 100 μm or greater.
4. heavy industries such as shipbuilding, construction steel structures or large equipment in the steel industry require a galvanised layer thickness of 150μm or more.
