ASTM A653 DX51D+Z 0.7 mm × 1250 mm Z275 High-Zinc-Coated Galvanized Steel Coil
ASTM A653 DX51D+Z 0.7 mm × 1250 mm Z275 High-Zinc-Coated Galvanized Steel Coil
Hot-dip galvanized GI coils for construction projects, structural profiles and roof cladding. Stable corrosion resistance, comply with ASTM A653 and JIS G3302. EN 10204 3.1 MTC provided for project submission. Enquire for current stock, thickness range and factory direct price.
- Mill Test Certificate Provided
- Strict Quality Inspection
- Custom Sizes Available
- On-Time Global Delivery
Sky Steel Group manufactures and exports hot-dip galvanized steel coils and sheets across Regular Spangle, Minimized Spangle, and Zero Spangle surface finishes. Engineered for corrugated roofing, structural C/Z purlins, HVAC ductwork, cable trays, and automotive/appliance stamping, our galvanized coils feature zinc coating weights from Z30 to Z275 (up to Z600 g/m² upon request) in thicknesses from 0.12 mm to 4.0 mm. All products comply with ASTM A653, EN 10346 (DX51D+Z / S350GD+Z), JIS G3302 (SGCC), and GB/T 2518.
Spangle Metallurgy, Forming & Corrosion Resistance
The spangle pattern is formed during the cooling solidification of the molten zinc bath. Regular spangle features distinct snowflake-like zinc crystal grains, delivering an aesthetic industrial appearance widely favored for exposed roofing, fencing, and air ducts. Zero spangle is achieved using an antimony/lead-free zinc bath and rapid cooling, producing a uniform matte surface.
For high-precision post-painting and appliance applications, our Skin-Passed Zero Spangle coils undergo an inline four-high temper rolling mill pass. This eliminates the yield point elongation, flattens zinc crystal boundaries, and provides an ultra-smooth substrate for high-gloss powder coating, automotive panel stamping, and pre-painted steel (PPGI) production.
Galvanized Steel Coil (Spangle & Zero Spangle) Specifications
| Item | Available Range |
|---|---|
| Product | Hot-Dip Galvanized Steel Coil & Sheet (GI Coil) |
| Spangle Structure | Regular Spangle (Big) / Minimized Spangle (Small) / Zero Spangle / Skin-Passed Extra Smooth |
| Standard | ASTM A653 / EN 10346 / JIS G3302 / GB/T 2518 / AS 1397 |
| Steel Grade | DX51D+Z, DX52D+Z, DX53D+Z / SGCC, SGCD / S250GD, S350GD, S550GD (Full Hard) / ASTM A653 CS, SS Gr.50 |
| Thickness | 0.12 mm – 4.0 mm (Tolerance: ±0.01 – ±0.02 mm) |
| Width | 600 mm – 1500 mm (Custom precision slit coils 20 mm – 600 mm) |
| Zinc Coating Mass | Z30 – Z275 g/m² (Triple spot average; heavy zinc Z350, Z450, Z600 available) |
| Surface Treatment | Chromated Passivation (Cr3+ / Cr6+ Free) / Anti-Fingerprint (AFP) / Oiled / Unoiled / Skin-Passed |
| Coil Inner Diameter (ID) | 508 mm (20″) or 610 mm (24″) with steel core sleeve options |
| Coil Weight | 3.0 – 8.0 Metric Tons (Max 10 MT; baby coils 1.0 – 3.0 MT) |
| Mechanical Properties | Tensile Strength: 270 – 600 MPa / Yield Strength: 140 – 550 MPa / Elongation: ≥16% – 38% |
| Processing Capabilities | High-Speed Slitting / Precision Cut-to-Length Sheets / Corrugated Tile Roll-Forming / Hole Punching |
| Application | Corrugated Roofing & Cladding / Floor Decking / HVAC Air Ducts / Cable Trays / C & Z Purlins / Appliance Panels |
| Inspection & Certificate | EN 10204 3.1 MTC / ISO 9001 / CE / Third-Party Inspection (SGS, BV, Intertek) |
| Packing | Eye-to-Sky or Eye-to-Wall Seaworthy Packing / Galvanized Steel Side Guards / Heavy-Duty Wooden Skids |
| Customization | Custom Width Slitting / Stamped Cut Sheets / High Zinc Coating (Z275+) / Strict Flatness Tolerance |
Need a Fast Quote for Galvanized Steel Coils?
Send us your required spangle type (Regular / Zero), thickness, width, zinc coating (Z40–Z275), and coil quantity for an immediate factory CIF/FOB price.
Where Are Spangle and Zero Spangle Galvanized Coils Used?
Hot-dip galvanized steel coils combine the structural strength of carbon steel with sacrificial cathodic zinc protection. From raw snowflake spangles for building cladding to ultra-smooth zero spangle for appliance panels, our coils cover the full spectrum of industrial and construction applications.
Surface Spangle Structure: Regular Spangle vs. Zero Spangle
Regular Spangle (Left): Features distinct snowflake crystal patterns formed during natural air cooling. Highly preferred for unpainted corrugated roofing, HVAC ducts, and exterior architectural applications.
Zero Spangle (Right): Produced with a lead-free zinc bath and temper mill skin-passing, creating an ultra-smooth, uniform satin finish that prevents paint pinholing and orange-peel texture during downstream powder coating and appliance stamping.
Continuous Galvanizing Line, Precision Slitting & Mill Stock
Equipped with automated continuous hot-dip galvanizing lines and high-precision CNC slitting shears. We produce custom slit coils down to 20 mm width with strict burr-free edge tolerances (±0.05 mm), packaged in solid steel strapping bands and organized on dedicated wooden cradles for damage-free warehouse crane handling.
Building Construction: Corrugated Roofing, Siding & Floor Decking
High-strength structural galvanized coils (S350GD+Z / S550GD Full Hard) serve as raw material for roll-forming trapezoidal roofing sheets, wall cladding, composite floor decking, and C/Z purlins on industrial logistics warehouses and commercial steel buildings.
Multimodal Export Logistics: Breakbulk Vessel & 20GP Container Lashing
Full export protection against oceanic humidity and salt fog. Heavy coils (3–8 MT) are secured inside 20GP containers with timber cradles, steel chocks, and high-tensile wire rope cross-lashing, or stacked tightly within breakbulk vessel cargo holds with anti-scuff wooden dunnage to guarantee zero rust and zero deformation upon arrival.
Frequently Asked Questions About ASTM A653 DX51D+Z 0.7 mm × 1250 mm Z275 High-Zinc-Coated Galvanized Steel Coil
1. What is the practical difference between Regular Spangle and Zero Spangle?
The difference is strictly in surface aesthetics and post-processing suitability:
• Regular Spangle (含锌花 / 大锌花): Features visible, shiny snowflake crystalline patterns. It is widely chosen for unpainted outdoor applications (corrugated roof tiles, air conditioning ducts, cable trays, grain silos) where the traditional galvanized pattern is desired.
• Zero Spangle (无锌花 / 零锌花): Produced with a lead-free zinc bath, resulting in a uniform matte gray surface. When skin-passed (temper-rolled), it provides an ultra-flat surface without crystal boundaries, making it the standard substrate for powder coating, appliance outer panels, and PPGI color coating without surface texture read-through.
2. How do I select the right zinc coating weight (Z30 to Z275+)?
Zinc coating weight directly determines atmospheric corrosion service life:
• Light Zinc (Z30 – Z60 g/m²): Best for indoor appliances, dry internal ductwork, or immediate post-painting.
• Standard Zinc (Z80 – Z140 g/m²): Standard commercial grade for agricultural roofing, C/Z purlins, and general sheet metal forming.
• Heavy Zinc (Z180 – Z275 g/m² / Z350–Z600): Recommended for heavy outdoor exposure, coastal/humid zones, infrastructure floor decking, and high-durability roofing requiring 20+ years of rust protection.
3. What surface passivation and oiling treatments do you provide?
To prevent wet-storage white rust during ocean transit and storage:
• Chromated Passivation (Cr3+ RoHS / Cr6+): Standard chemical conversion film for atmospheric corrosion resistance.
• Anti-Fingerprint (AFP): Organic/inorganic acrylic coating (transparent or tinted) that prevents fingerprint smudging and enhances lubricity during roll-forming.
• Oiled / Unoiled: Electrostatic vanishing oil (500–1500 mg/m²) for severe marine transit, or unoiled/dry for immediate painting.
4. What steel grades are available for deep drawing vs structural roofing?
We supply both forming and structural grades:
• Commercial & Deep Drawing: DX51D+Z (lock-forming quality), DX52D+Z (drawing), DX53D+Z (deep drawing), and ASTM A653 CS Type A/B for severe bending and stamping without zinc flaking.
• Structural & High Strength: S250GD, S350GD, and S550GD (Full Hard G550, yield strength ≥550 MPa) engineered for lightweight, high-load corrugated roofing tiles and structural floor decking.
5. Can you supply custom slit widths and flat cut-to-length sheets?
Yes. Our processing center provides:
• Slit Coils: Precision slitting from 20 mm to 600 mm with tight edge burr control (±0.05 mm), strapped on wooden pallets.
• Cut Sheets: High-speed cut-to-length leveling into flat sheets (length 500 mm – 6000 mm) packed in seaworthy bundles with metal corner protectors.
6. How are galvanized steel coils packaged and loaded for ocean container shipping?
Coils receive 7-layer seaworthy export packaging: inner anti-rust paper + waterproof polyethylene film + corrugated paperboard + inner/outer galvanized steel protective rings + corner angle guards + 3 radial & 3 circumferential high-tensile steel straps. For container loading (20GP, max 26–28 MT), coils rest on solid timber cradles and are locked with steel wire rope turnbuckles and wooden chocks to prevent any movement at sea.
