Please note: Generally speaking, the thicker the galvanized sheet, the greater the allowable tolerance. The requirements for its yield degree, tensile coefficient, etc. are also different. The tolerances of length and width should be within 5 millimeters.

Types of galvanized sheet materials

The commonly used galvanized steel grades are:

Commercial sheet materials (CQ), such as DX51D+Z, SGCC;

Forming steel

Structural GI sheet (HSLA)

Deep-drawn steel plate (DDQ)

Ultra-deep drawing steel (EDDS), etc

Types of galvanized sheets

Galvanized steel plates come in different types. In terms of manufacturing processes, we divide them into hot-dip galvanized steel sheets and electro-galvanized steel sheets. Hot-dip galvanized steel sheets are mainly used in industries such as construction, home appliances, automobiles, and light industry.

Hot-dip galvanized steel sheet

Hot-dip galvanized steel is made by immersing steel plates in a molten zinc bath at approximately 500℃, causing a layer of zinc to adhere to the surface. This is the continuous galvanizing process. It will form a protective zinc layer on the surface, giving it good paint adhesion and solderability. It is the most widespread and cost-effective method to extend the service life of steel plates. The following is a workflow for your reference.

Electro-galvanized steel sheet

Electro-galvanizing, also known as cold galvanizing, is a process that uses electrolysis to form a uniform and dense coating on the surface of metals. The anti-corrosion zinc coating can protect steel parts from oxidation and corrosion. In addition, it can also meet the purpose of decoration. However, the zinc coating of electro-galvanized steel sheets is only 5 to 30 grams per square meter. So its corrosion resistance is not as good as that of hot-dip galvanized steel sheets.

The differences between hot-dip galvanized steel sheets and electro-galvanized steel sheets

• Anti-corrosion

The thickness of the galvanized coating is one of the most important factors affecting corrosion resistance. The thicker the zinc coating is, the better the corrosion resistance will be. The thickness of the general hot-dip galvanized coating is greater than 30g/m ², and can even reach up to 600g /m ². However, the zinc coating of electro-galvanized steel is only 5 to 30 grams per cubic meter thick. So the former type of steel plate is much more corrosion-resistant than the latter type. In Wanzhi Steel, the maximum zinc coating is 275 g/m ² (Z275 galvanized steel plate).

• Operation method

Hot-dip galvanized steel sheets are galvanized in a molten zinc bath at around 500 degrees, while electro-galvanized steel sheets are treated at room temperature through electroplating or other methods. This is why electro-galvanizing also refers to the cold galvanizing process.

• Surface smoothness and adhesion

The surface of electro-galvanized steel sheet appears smoother than that of hot-dip galvanized steel sheet. However, its adhesion is not as good as that of hot-dip galvanized sheet. If you only want to galvanize one side, you can choose electroplating. However, if hot-dip galvanizing is adopted, both sides will be fully coated with zinc.

• Application

Electro-galvanizing is suitable for small workpieces. Electro-galvanized sheets are suitable for applications that require high gloss and interior use, such as ceilings, window or door frames, and automotive panels. Hot-dip galvanized steel plates are more corrosion-resistant and are a good choice for outdoor environments. Its uses include roofs, doors, drainage ditches, pipes, etc.