Galvanized Steel Coil FAQ

Can galvanized steel coil be oiled?

Yes, it can be oiled. 8-20 grams per square meter. Oiling can prevent oxidation of galvanized sheet in a short time.

Do you accept or not accept galvanized coating testing?

Yes, tested for zinc coatings. We can send galvanized steel coil samples to the laboratory required by customers. Or China SGS.

The difference between hot-dip galvanized steel coil and electro-galvanized steel coil

Hot dip galvanized steel coil. The thin steel coil is immersed in the molten zinc bath, and the thin steel coil with a layer of zinc is attached to the surface. The current production mainly adopts the continuous galvanizing process, that is, the rolled steel plate is continuously immersed in the hot-dip galvanizing tank to make galvanized steel coils.

There is a big difference in the amount of galvanizing between hot-dip galvanized sheet and electro-galvanized sheet. The amount of hot-dip galvanizing should not be too small, generally the minimum on both sides is 50-60g/m2, and the maximum is 600g/m2. The galvanized layer of the electro-galvanized sheet can be very thin, the minimum is 15g/m2, but if the coating is thick, the production line speed is very slow, which is not suitable for the technological characteristics of modern units, generally the maximum is about 100g/m2. Because of this, the production of electro-galvanized sheet is greatly restricted.

Hot-dip galvanized steel sheet generally has a thicker zinc layer, about 10um or more, and has strong anti-corrosion ability. So it is a commonly used galvanizing process. The electro-galvanized sheet is very thin, about 3-5um, and the surface of hot-dip galvanized is rough and bright. If there are spangles, the plating is smooth and matt (dirty).

Galvanized Spangle Type

Galvanized with regular spangle, zinc-coated from 30g to 275g (g90). Thickness from 0.15mm to 2.0mm. Ordinary spangle galvanizing can be used in hot and humid places outdoors. For example, fences, roofs, garage doors, etc.

Galvanized Zero spangles, this glossy GI, galvanized from 30g to 2755g (g90). Thickness from 0.12mm to 0.25mm. It can also be used outdoors. Currently mainly exported to Southeast Asia and Africa. It's cheaper than regular spangle gi. The product can be post-processed, for example, into stone-coated tiles.

How long do galvanized regular and zero spangles last?

The service life depends on the range of application. Generally 5-10 years do not lose zinc. If the incision is treated, the service life is more than 10 years.

What are big spangle and small spangle?

Large spangles are regular spangles. Large spangles can be produced according to the normal production process. The diameter of the crystal nucleus is not less than 0.2mm; the diameter of the crystal nucleus is less than 0.2mm, which is called a small spangle. Such spangles are generally not identifiable with the naked eye.