Difference Between Hot Dipped Galvanized Wire and Electro Galvanized Wire

Anyone who wants to buy the galvanized steel wire has to know that GI wire is divided into hot dipped galvanized steel wire and electro galvanized steel wire. What’s the difference between them? Let’s review it together.

1. Conception

After drawing forming, pickling and rust removal, and high temperature annealing of a low carbon steel wire rod, it will be galvanized to complete the final step.

When it chooses to be galvanized at high temperatures, it’s called the hot dipped galvanized steel wire.

When it chooses to be cooled to galvanize, it’s called the electro galvanized steel wire, also known as cold galvanized steel wire.

2. Making Method

Hot-dip galvanized wire is immersed in the molten zinc solution at about 500°C and raised for a certain period of time to be galvanized. In this case, the zinc serves as a barrier layer on top of the steel to prevent corrosive substances from reaching the underlying steel or iron.

Electro galvanized wire is gradually plated on the metal surface through the unidirectional current in the plating tank at room temperature. The zinc layer is guaranteed to adhere to the surface of the steel to achieve protection against corrosion.

3. Thickness of Zinc

Generally, the thickness of hot dipped galvanized wire is thicker, often more than 35 μm, or even as high as 275 μm. Sometimes, it can be up to 10 times thicker than electro galvanized coating. Besides, the thickness is uneven under the condition of fast production speed.

Electro galvanized wire has a thin zinc layer of 5~15 μm. It is usually manufactured at a slow speed but the zinc layer is evenly distributed.

4. Corrosion Resistance

As we know, the thickness of zinc coating plays an important role in resisting corrosion and rust. The thicker the zinc layer, the stronger the corrosion resistance. Therefore, it can be clearly inferred that the hot dipped galvanized wire is more resistant than the electro galvanized wire.

5. Service Life

The ability to prevent rust is closely related to longevity. The hot dipped galvanized wire has a much longer life, averaging between 20 to 50 years.

However, the lifespan of electro-galvanization wire is shorter, ranging from several months to a few years only.

6. Flexibility

The hardness is much reduced under the operation of high temperature so that the hot-dip galvanized wire is flexible and ductile enough to be further processed.

Instead, the electro galvanized wire remains bigger hardness and higher precision.

7. Appearance

When the process is complete, the finished coating of hot dipped galvanized wire is dark, slightly rough, and dull. Sometimes there may exist many small zinc blocks, water lines, and drop tumors. Its color is silver-white.

The surface of electro galvanized iron wire is bright, smooth, and shiny. Its color is silver-white with yellow.

8. Cost

Significantly hot-dip GI wire is always more expensive than electro galvanized one (approximately 40% more expensive for comparable products). Because it needs more intensive galvanizing process and offers greater resistance to rust and corrosion.

9. Application

Generally, hot-dip galvanizing products are more widely used in outdoor environments that require strong corrosion resistance, such as transportation, building, electric power, energy,  automobile, petrochemical, and other industries. And it is also popular in harsh or extreme environments.

But the electro-galvanized steel is more suitable for indoor environments that require general anti-corrosion, which makes it ideal for architectural or aesthetic applications.

Conclusion

To know more about the differences between hot-dip GI wire and electro GI wire, will be greatly useful to enrich your knowledge and help to complete your purchase. If you still have some other confusion, welcome to consult Wanzhi Steel for more details.