Galvanized Steel Coil (GI Coil) – DX51D / Z275 / G90 Supplier

    Galvanized steel strip is ordinary steel strip pickling, galvanized, packaging and other processes of processing, has good corrosion resistance, such as: light steel keel, guardrail peach-shaped column, sink, rolling shutter door, bridge and other metal products.

    The production process of galvanized coil mainly includes the following steps: steel coil pickling, cleaning, pretreatment, baking, zinc dipping, cooling, coil formation and so on. Put the steel coil to be galvanized into the acid solution for pickling, after pickling, the surface of the steel coil will remain acid, chloride ions and other harmful substances, need to use water to wash, put the cleaned steel coil into the pretreatment tank for surface treatment, the surface of the steel coil will have a protective film, the steel coil into the molten zinc solution for dipping and plating, in order to achieve the ideal galvanized quality. Cooling is carried out to make the zinc layer on the surface of the steel coil solidify quickly to ensure the quality of the coating.

    In order to ensure product quality, we will arrange professional personnel to check product quality, packaging, weight, hardness, etc., according to customer requirements of product specifications, looking for high-quality and cheap cooperative factories in China, to provide customers with one-stop procurement services and quality assurance.

    Excellent packaging: waterproof paper and plastic film + iron cover + at least three strapping straps + strapping straps fixed on iron or wood pallets can effectively protect products from corrosion and various climate changes during transportation. Generally speaking, we ship from Shanghai, Tianjin, Qingdao and Ningbo ports. We have worked with many experienced shipping companies for a long time to find the most suitable mode of transportation for you.

FAQ:
1.What is galvanized coil? What is its core anti-corrosion principle?
    Galvanized coil refers to steel products with a zinc layer coated on the surface of cold-rolled or hot-rolled steel sheet/strip through hot-dip galvanizing or electro-galvanizing processes. The core anti-corrosion principle is sacrificial anode protection, where the zinc layer preferentially oxidizes, forming a dense protective film of zinc oxide and zinc carbonate. This film isolates the base steel sheet from air and moisture corrosion, significantly extending the service life of the steel.
2.What are the differences between hot-dip galvanized coils and electro-galvanized coils? How should one choose the right type for export orders?
    The core differences lie in the galvanizing process, zinc layer characteristics, and applicable scenarios. Export selection should be based on customer needs:
Hot-dip galvanized coils: Thicker zinc layer (typically ≥80g/㎡), strong adhesion, and excellent corrosion resistance, suitable for long-term exposure scenarios such as outdoor steel structures, containers, and construction projects. They are the mainstream choice for overseas infrastructure projects.
Electro-galvanized coils: Thinner zinc layer (typically 10-50g/㎡), smooth and flat surface, and high precision, suitable for products with high requirements for appearance and dimensional accuracy, such as appliance casings, automotive parts, and electronic equipment.
3.How is the zinc coating thickness marked on galvanized coils? What are the commonly used international testing standards?
    Zinc coating thickness is usually marked based on the weight of the zinc coating per unit area. Hot-dip galvanizing commonly uses "total weight on both sides" (e.g., 120g/㎡, 275g/㎡), while electro-galvanizing usually indicates the weight on one side. Mainstream international testing standards include: ISO 1461 (hot-dip galvanized coating standard), ASTM A123 (American hot-dip galvanized structural steel standard), and EN 10346 (European continuous hot-dip galvanized steel strip standard). For export orders, the required standard version must be specified in advance.
4.How to avoid "white rust" during the transportation and storage of galvanized coils?
    White rust is a white powdery form of zinc oxide that forms when the galvanized layer becomes damp. It affects the product's appearance and corrosion resistance. Special protection is needed for export transportation (especially by sea): ① Keep the warehouse dry and well-ventilated during storage, and elevate the steel at the bottom by 10-15cm to prevent contact with ground moisture; ② Wrap tightly in waterproof and moisture-proof packaging film before transportation, and include a desiccant; ③ Avoid open-air storage, and choose sealed containers for sea transportation to prevent seawater and moisture intrusion; ④ If the product cannot be used in the short term, apply rust-preventive oil to the surface.
5.What are the common specifications for galvanized coils? Can they be customized according to the needs of export customers?
    Standard specifications must conform to international standards to facilitate customer-friendly production: ① Thickness: 0.12 - 3.0mm (cold-rolled base material), 3.0 - 12.0mm (hot-rolled base material); ② Width: 1000mm, 1219mm, 1500mm, etc., standard widths; ③ Length: Customized into coils according to customer requirements (typically 2-5 tons per coil). Customization for export is supported. Dimensions, zinc layer thickness, surface treatment (such as passivation, oiling), etc., can be adjusted according to customer requirements. Minimum order quantity must be confirmed in advance.
6.What product certifications and customs declaration documents are required for exporting galvanized coils?
    Essential export documents vary depending on the requirements of the destination country, but the core documents include: ① Product quality certificates: material certificate, galvanized layer test report, ISO quality system certification; ② Customs declaration documents: commercial invoice, packing list, bill of lading, certificate of origin (some countries may offer tariff preferences); ③ Special certifications: CE certification is required for export to the EU, ASTM certification is required for export to the US, and a third-party testing report conforming to local industrial standards is required for export to the Middle East and other regions.