Hot Dipped Galvanized Steel
Hot Dipped Galvanized Steel — HDG Coil & Sheet
High-quality hot-dipped galvanized steel for construction, home appliances, automotive, and general manufacturing. Z40 to Z275 coating weights. Full mill certificates provided with every shipment.
What Is Hot-Dipped Galvanized Steel?
Continuous Hot-Dip Galvanizing (HDG) Process
Hot-dipped galvanized steel (HDG) is produced by passing cold-rolled steel strip through a bath of molten zinc at approximately 450°C. The zinc coating forms a metallurgical bond with the steel, creating a corrosion-resistant layer that also provides sacrificial protection at cut edges and scratches.
HDG steel offers the best balance of corrosion resistance, formability, and cost-effectiveness, making it the most widely used coated steel product globally. Perfect for applications requiring long service life in outdoor or humid environments.
Qiaosi Steel supplies HDG in coil, sheet, and slit strip forms. Standard spangle types: regular spangle, minimized spangle, and zero spangle (for paint-ready surfaces).
Standards: EN 10346 / ASTM A653 / JIS G3302 / GB/T 2518.
Corrosion Protection
Sacrificial zinc protection at edges & scratches
Excellent Formability
Roll-forming, stamping, bending without delamination
Long Service Life
15–30+ years outdoors depending on coating
Paint-Ready
Ideal substrate for PPGI / color coating
Cost-Effective
Lower lifecycle cost vs. stainless steel
HDG Manufacturing Process
Continuous Hot-Dip Galvanizing Line — 8 Steps
Cleaning
Alkaline degreasing & pickling to remove oil & oxides
Annealing
Controlled atmosphere furnace ~750°C to restore ductility
Galvanizing
Immersion in molten zinc bath at ~450°C
Air Knife
High-pressure air jets control coating weight precisely
Cooling
Controlled cooling tower allows zinc spangle formation
Skin Pass
Temper rolling for flatness & surface texture
Treatment
Passivation & oiling (optional) for storage stability
Inspection & Coil
Edge trimming, inspection, and final coil packaging
Hot Dipped Galvanized Steel — Technical Specifications
Full Range of HDG Product Parameters
📐 Standard Dimensions
| Parameter | Value |
|---|---|
| Thickness | 0.12 – 6.00 mm |
| Width | 600 – 1,800 mm |
| Inner Diameter (ID) | 508 mm / 610 mm |
| Coil Weight | 3 – 15 MT |
| Standard Length | Coil or sheet (custom lengths) |
⚖️ Coating Weight (Both Sides)
| Code | Min Triple-Spot (g/m²) | Approx. Thickness (μm) | Typical Use |
|---|---|---|---|
| Z40 | 40 | ~5.6 | Very light indoor / short-term storage |
| Z60 | 60 | ~8.4 | Light indoor |
| Z80 | 80 | ~11 | General indoor |
| Z100 | 100 | ~14 | Appliances / Light construction |
| Z140 | 140 | ~20 | Construction / Roofing |
| Z180 | 180 | ~25 | Industrial / Outdoor structures |
| Z200 | 200 | ~28 | Heavy industry / Coastal |
| Z275 | 275 | ~39 | High corrosion / Agricultural / Marine |
🔩 Base Metal Grades & Equivalents
| Grade (EN 10346) | Yield (MPa) | Tensile (MPa) | Elong (%) | GB | ASTM | JIS |
|---|---|---|---|---|---|---|
| DX51D+Z | 140–300 | 270–500 | ≥22 | DX51D+Z | CS-A | SGCC |
| DX52D+Z | 140–300 | 270–420 | ≥26 | DX52D+Z | CS-B | SGCD1 |
| DX53D+Z | 140–260 | 270–380 | ≥30 | DX53D+Z | DDS | SGCD2 |
| DX54D+Z | 120–220 | 260–350 | ≥36 | DX54D+Z | EDDS | SGCD3 |
| S350GD+Z | ≥350 | ≥420 | ≥16 | S350GD+Z | SS 50 / HSLAS | SGC440 |
| S550GD+Z | ≥550 | ≥560 | ≥12 | S550GD+Z | SS 80 | SGC570 |
🎨 Surface Treatment Options
| Treatment | Description |
|---|---|
| Passivation (Chromate) | Prevents white rust, improves storage stability |
| Oiling | Extra moisture protection, 0.5–2.0 g/m² |
| No Passivation (Dry) | For subsequent painting / PPGI substrate |
| Anti-Fingerprint | For visible appliance & display panels |
✨ Spangle Types
| Type | Appearance | Best For |
|---|---|---|
| Regular Spangle | Visible crystalline zinc flowers | General construction, hidden parts |
| Minimized Spangle | Suppressed spangle, fine uniform texture | Visible panels, painted surfaces |
| Zero Spangle | No visible spangle, smooth matte finish | PPGI substrate, automotive, appliances |
Mill test certificates (MTC / EN 10204 Type 3.1) provided with every shipment. Third-party inspection welcome at origin.
Hot Dipped Galvanized Steel — Applications
Where HDG Steel Is Used
Construction
Roofing, wall panels, floor deck
Home Appliances
Washer casings, fridge panels, AC units
Automotive
Underbody, heat shields, brackets
Cable Trays
Raceways, cable management systems
Solar Mounting
PV panel racking structures
Industrial Pipes
HVAC ducts, ventilation systems
Agriculture
Silos, livestock equipment, fencing
Infrastructure
Railway, traffic barriers, signage
Hot Dipped Galvanized Steel — Packaging & Shipping
Export-Standard Packaging for Safe Transit
General Package
Water-proof Paper & Plastic Film
Steel Strip Outside
Standard Export Package
Shipping via Container
Shipping via Bulk Carrier
Each bundle tagged with: MTC number, coil ID, size, coating weight, net/gross weight.
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