Galvanized Steel - How is it made?

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How Is Galvanized Steel Made?

The Objective of Galvanization

“Galvanization” means the process of coating steel with a layer of zinc. The zinc is meant to protect the steel from corrosion.   Galvanization can add years of life to a product, depending on its use and environment. This is a highly desirable trait and consequently, it is commonly available. Depending on the type of galvanization needed, a thin or thick layer of zinc will be applied. However, in all cases, the zinc must bond firmly to the steel with no capability of chipping or peeling.

Hot-Dip Galvanization

Hot-dip galvanized steel , a very common galvanizing production technique, deposits a thick layer of zinc on a steel object. The process begins with heating zinc until it forms a molten bath at a temperature of around 850 degrees Fahrenheit. Then workers place the piece of steel to be galvanized in the bath and let it sit until it reaches the temperature of the bath. At that point, workers remove the object, which now has a layer of zinc carbonate firmly bonded to it. In some cases, the steel is then quenched in a dilute chromate solution. In all cases, the steel must be cleaned thoroughly before dipping in the hot bath.

Electro galvanization

The electro galvanization process uses electricity to bond zinc to steel. In this process, workers run DC electricity through a zinc-salt solution. The electricity runs through an anode and then to the steel, which acts as a cathode. The anode in electro galvanization can be either a block of zinc, in which case it serves also as the zinc component of the zinc-salt solution. It can also be a block of lead, in which case workers must constantly add zinc to the solution. In both cases, the force of electricity running through the anode to the steel causes zinc to dissolve and bond to the steel. During this process, dissolved particles of zinc run along the line of current. This brings them to the steel and deposits them on it. The constant DC electricity causes zinc particles to bond tightly to the steel, creating a very thin layer. As in hot-dip galvanization, the galvanized steel must be thoroughly cleaned prior to this process.


Carlson Manufacturing Inc. Has been working with Galvanized Steel for over 50 years.   Call us if we can help meet your needs.




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