GI Coil Zinc Coated Steel Sheet Z40–Z275 DX51D SGCC for Roofing & Construction
Galvanized steel coil (GI coil) is a carbon steel sheet coated with a protective layer of zinc through a hot-dip galvanizing process. This zinc layer provides excellent corrosion resistance, making it suitable for both indoor and outdoor applications.
Compared with untreated steel, galvanized steel significantly improves durability, reduces maintenance costs, and extends service life, especially in humid or coastal environments.
| Item | Value |
|---|---|
| Standard | AiSi, ASTM, BS, DIN, GB, JIS |
| Place of Origin | China |
| Zinc Coating | Z30~275 |
| Type | Steel Coil |
| Technique | Cold Rolled |
| Surface Treatment | Chromated / Oiled / Anti-fingerprint |
| Application | Roofing sheets / corrugated sheets / Steel structures |
| Special Use | High-strength Steel Plate |
| Width | 0.6m-3m or as required |
| Length | 4m-12m or as required |
| Tolerance | ±1% |
| Type | Hot-Galvanized Steel Coils |
| Grade | DX51D, SGCC, ASTM A653 |
The zinc coating acts as a barrier and sacrificial layer, protecting the steel from rust and oxidation.
Galvanized steel offers a lower lifecycle cost compared to stainless steel or coated alternatives.
Suitable for:
- Roll forming
- Cutting
- Punching
- Welding
- Big Spangle (visible pattern, decorative use)
- Regular Spangle (standard industrial use)
- Zero Spangle (smooth surface for painting)
Our galvanized steel coils are widely used across multiple industries:
- Construction: Roofing sheets, wall panels, corrugated sheets, gutters, and ventilation ducts
- Industrial: C purlins, steel structures, highway guardrails
- Automotive: Car body parts, chassis components
- Home Appliances: Back panels of refrigerators, washing machines, electrical cabinets
We strictly control the production process from raw material selection to final packaging. All products undergo rigorous testing including:
- Tensile Strength Test
- Zinc Coating Uniformity Test (Preece Test)
- Salt Spray Corrosion Test
To ensure the product arrives in perfect condition:
- Inner Packaging: Anti-rust oil film + water-proof kraft paper
- Outer Packaging: Galvanized steel sheet wrapping + iron rings reinforcement
- Loading: Standard export sea-worthy packaging
Port of Loading: Tianjin / Shanghai / Qingdao, China
Delivery Time: 15-25 days after receiving deposit or LC
A:
- Z275 (according to EN standard) means the total zinc coating weight on both sides is 275 grams per square meter (approximately 138g/m² per side)
- G90 (according to ASTM standard) means the total zinc coating weight is 0.90 ounces per square foot, which is approximately 275g/m² as well
In simple terms, the higher the number, the thicker the zinc layer and the better the rust protection. Common options range from Z40 (light protection, suitable for indoor use) to Z275 (heavy protection, suitable for outdoor roofing)
A: Yes. We offer various grades to meet different forming requirements:
- DX51D / SGCC: Suitable for simple bending and general forming
- DX52D / SGCD: Suitable for moderate drawing and forming
- DX53D / DX54D: Suitable for deep drawing and complex shapes
Please inform us of your specific application, and we will recommend the most suitable grade and temper
A: We offer three common surface treatments:
- Oiled: A thin layer of oil is applied to prevent rust during storage and transportation. Suitable for most industrial applications
- Non-oiled / Dry: No oil applied. Suitable for applications that require immediate painting or welding without degreasing
- Anti-fingerprint (AFP): A transparent protective coating is applied to the surface, which resists fingerprints, improves corrosion resistance, and provides a smoother touch. This is commonly used for home appliances and decorative applications
A: We have a strict quality control system. Before shipment, each batch undergoes:
- Spectrometer analysis: To verify chemical composition
- Tensile testing: To ensure yield strength and elongation meet the standard
- Salt spray test: To verify the uniformity and corrosion resistance of the zinc coating
- Third-party inspection: We welcome inspections by SGS, BV, or any other accredited agency at the buyer's request
A: Our standard MOQ is 25 tons (one 20-foot container). However, for samples or trial orders, we can accommodate smaller quantities such as 5-10 tons to help new customers evaluate our product quality. Please contact us to discuss your specific needs
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Have questions about our products or want to discuss a custom order? Our team is ready to help you.