Electro Galvanized vs. Hot Dipped Galvanized Steel

Electro-galvanized steel and hot-dipped galvanized steel are two popular types of coated steel, but they differ in process and performance.

Electro-galvanized steel is coated with zinc through an electroplating process, which provides a thinner, more precise layer. This results in a smoother finish but offers less corrosion resistance. Hot-dipped galvanized steel is submerged in molten zinc, creating a thicker, rougher layer. This creates a thicker, rougher layer that offers better protection against rust.

In this article, we will explore these differences in more detail, including their advantages, disadvantages, and ideal uses.

Process of Electro Galvanized vs Hot Dipped

Electro Galvanized Steel

It is produced by placing the steel in an electroplating bath. In this bath, a zinc layer is applied using an electrical current. The steel acts as a negative electrode, and zinc ions attach to its surface. This process occurs within a controlled environment, typically indoors. 

The electroplating method allows for a thin, uniform zinc coating that provides a smooth finish. The steel used for electro-galvanizing is usually cold-rolled, and the process is precise, making it ideal for applications requiring accuracy and aesthetics.

Hot-Dipped Galvanized Steel

It is made by dipping the steel into a bath of molten zinc. Firstly the steel is cleaned and then immersed in the molten zinc, which bonds to its surface. This process usually takes place in large industrial facilities, often in well-ventilated areas due to the high temperatures involved. 

The steel used is usually prepared with a rougher surface to help the zinc adhere better. As a result, the coating is thicker and less uniform compared to electroplating, but it covers the steel more completely.

Performance of Electro Galvanized vs Hot Dipped Steel

Appearance

Electro-galvanized steel has a smooth, shiny finish, which is often preferred for aesthetic applications like home appliances and automotive parts. 

Hot-dipped galvanized steel has a more textured, matte appearance. This rougher look is less suited for decorative use but is common in construction and industrial projects. 

Hot-dip galvanized steel often has visible spangles, giving it a patterned look. They form during the hot-dip galvanizing process as the molten zinc cools and crystallizes on the steel surface. 

Thickness

Hot-dipped galvanized steel typically has a thicker zinc coating than electro-galvanized steel. The hot dipping process allows for a more significant build-up of zinc, which enhances protection, but also adds to the weight. 

In contrast, electro-galvanized steel’s coating is relatively thin. This difference affects their performance in demanding environments. 

Corrosion Resistance

Hot-dipped galvanized steel offers better corrosion resistance compared to electro-galvanized steel. 

The thicker zinc layer from the hot dipping process acts as a more substantial barrier against environmental factors like moisture and salt. The thinner zinc coating in electro-galvanization wears away faster when exposed to corrosive elements.

• How long will electro-galvanized steel last?

It depends on the environment. Indoors, it can last 10-20 years or more without rust. In outdoor or humid conditions, it may only last a few years, as the thin zinc coating wears off faster. Regular maintenance can help, but it won’t last as long as hot-dipped galvanized steel in harsh environments.

Durability

Hot-dipped galvanized steel lasts longer due to its thicker zinc coating, which provides a stronger protective layer against wear and damage. This makes it ideal for heavy-duty uses.

Electro-galvanized steel may not withstand the same level of stress and environmental exposure over time. Its thinner coating makes it less resistant to physical damage and corrosion in demanding settings.

Painting

Hot-dip galvanized steel can be more difficult because the rough surface may require extra preparation to ensure the paint adheres properly. Electro-galvanized steel has a smooth surface to accept paint well.

Cost

Electro-galvanized steel is typically more affordable due to its thinner zinc coating and simpler production process. It’s a cost-effective option for applications where high durability and corrosion resistance aren’t critical, such as indoor use. 

In contrast, hot-dipped galvanized steel is more expensive but provides better long-term value for outdoor or heavy-duty applications thanks to its thicker, more protective coating.

Applications of Electro Galvanized vs Hot Dipped Steel

Electro Galvanized Steel

• Automotive parts (interior components, body panels)
• Home appliances (refrigerators, washing machines)
• Office equipment (desks, filing cabinets)

Hot Dipped Galvanized Steel

• Outdoor construction (bridges, guardrails)
• Utility structures (electric poles, water tanks)
• Agricultural equipment (trailers, fences)
• Industrial machinery (piping, heavy-duty frames)

How to Choose Electro Galvanized Steel or Hot Dipped Steel?

If you’re working on an indoor project, like furniture, home appliances, or office equipment, electro-galvanized steel is usually the better choice. It has a smooth, clean look that works well in spaces where appearance matters, and it will hold up just fine in a dry, controlled environment.

If your project involves outdoor structures, like fences, roofs, or anything exposed to the elements, hot-dipped galvanized steel is the way to go. It has a thicker protective layer that can handle rain, humidity, and salty air near the coach.

The Difference Between SECC and SGCC

Galvanized steel sheets are made by applying a layer of zinc to cold-rolled steel sheets known as SPCC. Based on the galvanizing method used, these sheets are classified into electro-galvanized steel sheets (SECC) and hot-dip galvanized steel sheets (SGCC).

SECC is produced by electroplating zinc onto the steel sheet. SGCC is made by dipping the steel sheet into molten zinc. The differences between SECC and SGCC are similar to those between electro-galvanized and hot-dip galvanized steel we’ve discussed earlier. 

Your Project Partner

If you’re in the market for electro-galvanized or hot-dipped galvanized steel products, Steel Pro Group can provide high-quality products that meet industry standards. We offer a comprehensive range of durable and aesthetically pleasing steel solutions, including sheets, coils, and custom fabrications. Click here to get a quote today and discover how Steel Pro Group can help you achieve your goals.