“Steel” is a fundamental material in all industrial sectors, including construction, automotive manufacturing, and machinery. Thanks to its strength and long service life, steel is widely chosen as the foundation for engineering and structural work around the world. However, despite its strength, there is a significant point of concern—moisture. When moisture and oxygen react with steel, it can lead to rust formation. Therefore, one of the most effective ways to prevent rusting in steel is through zinc coating and galvanization.
What’s the difference between zinc coating, galvanizing, and zinc plating?
In reality, the material used to coat steel surfaces to prevent rust is zinc—also known as “สังกะสี” (sangkasi) or “ซิงค์” (zinc) in Thai. These three names all refer to the same material. So, what about galvanizing?
The answer is:
The difference between zinc coating and galvanizing lies more in the coating process rather than the material itself.
At present, there are various methods for coating steel.
- Hot dip galvanized (HDG)
- Continuous Hot Dip Galvanizing
- Centrifuge galvanizing (Spinning)
- Electrogalvanizing
- Mechanical Coatings
- Zinc Spraying
- Zinc-Rich Paints
- Sherardizing
Each coating method varies depending on the shape of the steel to be coated, the installation area, and the intended use.
Zinc coating or zinc plating, commonly known as electroplating, is a method that involves coating steel with zinc using an electrical current. This process, known as electroplating, typically produces a coating thickness of about 5 to 10 microns.
It is most commonly used for applications where there is a low risk of rust, or where the steel is located indoors—such as in electrical appliances, nuts, bolts, and springs.
The galvanizing method offers long-term durability and is highly resistant to sunlight, rain, and even acidic environments. It is commonly used for large structural applications such as:
-
Utility poles
-
Steel fences
-
Roadside guardrails
-
Water pipes
-
Conduits for electrical, internet, or communication cables
-
Manhole covers
-
Steel grating
This is because galvanizing provides a thick protective coating, typically around 65 to 300 microns, which helps preserve the material and significantly extend its service life—often by several decades.
Siam Steel Galvanizing Co., Ltd. and Rayong Galvanizing Co., Ltd. provide galvanizing services using both Hot-Dip Galvanizing (HDG) and Spin Galvanizing methods. Their production processes meet international standards and are certified under ISO 14001:2015 as of 2025 (B.E. 2568).
They offer pickup and delivery services, with a strong focus on after-sales service and customer care.
Summary : Zinc plating, zinc coating, and galvanizing all involve coating the surface of steel with zinc to protect it from rust. The difference lies in the method of application, not the material itself.
If the steel is intended for outdoor use, requiring resistance to sunlight, rain, and acidic environments, the best option is Hot-Dip Galvanizing (HDG). This process includes up to 8 surface preparation steps to ensure strong zinc adhesion, resulting in a thick, durable coating that can extend the lifespan of the steel for several decades.
For smaller items like bolts, nuts, screws, springs, or nails, the Spin Galvanizing method is more suitable, as it’s designed for small parts that need uniform coating.
Both Siam Steel Galvanizing Co., Ltd. and Rayong Galvanizing Co., Ltd. offer galvanizing services using both Hot-Dip Galvanizing (HDG) and Spin Galvanizing techniques to meet all types of customer requirements.
In addition, Siam Steel Gratings Co., Ltd., a leading manufacturer of steel gratings in Thailand, offers integrated steel grating production and galvanizing services, providing a one-stop solution for durable, corrosion-resistant steel grating products.
Locations:
-
Head Office: Rama 9, Bangkok
-
Galvanizing Plants: Located in Samut Prakan, Saraburi, and Rayong
These strategic locations allow the companies to provide efficient service and logistics coverage across central and eastern Thailand.
If you are unsure whether galvanizing is suitable for your project, you can contact us for free consultation:
Phone : (+66) 02-705-8755
E-mail: ssgl@ssggalvanizing.com
Official Line: @ssggalvanizing (or click to add @LINE)
#SSG #SiamSteelGalvanizing
#HotDipGalvanizing #GalvanizedSteel #InternationalStandard #ZincCoating #GalvanizedSteelGrating
