Galvalume Steel Coil - Al-Zn Coated GL Coil AZ50-AZ185
Galvalume steel coil with 55% aluminum, 43.4% zinc and 1.6% silicon alloy coating (AZ50-AZ185). Provides 2-4× longer atmospheric corrosion life than standard galvanized steel in equivalent outdoor conditions. Excellent heat resistance to 315°C and superior solar reflectivity. Industry-standard material for metal roofing, solar mounting structures, pre-engineered buildings and PPGL substrate. ASTM A792 / EN 10346 / JIS G3321 certified.
| Product | Galvalume Steel Coil / GL Coil / Aluzinc Coil |
| Coating | AZ50 – AZ185 (50-185 g/m²) |
| Composition | 55% Aluminum + 43.4% Zinc + 1.6% Silicon |
| Thickness | 0.12 – 4.0 mm |
| Width | 600 – 1500 mm |
| Standard | ASTM A792, EN 10346, JIS G3321, GB/T 55441 |
| Surface | AFP (Anti-Finger Print) / Oiled / Chromate / Bare |
| Steel Grade | DX51D+AZ, DX52D+AZ, S350GD+AZ, S550GD+AZ, G550 |
| Coil ID | 508 mm / 610 mm |
| Coil Weight | 3 – 10 MT (customizable) |
55% Aluminum-Zinc Alloy Coated — AZ50 to AZ185 — Superior Corrosion Resistance for Roofing, Solar and Industrial Applications
What Is Galvalume Steel Coil?
Galvalume steel coil is a coated steel product produced by applying an aluminum-zinc alloy layer to cold rolled steel through a continuous hot-dip process. In international markets, it is also known as Aluzinc steel coil or GL coil. The standard coating composition is approximately 55% aluminum, 43.4% zinc and 1.6% silicon.
This alloy combines the barrier protection of aluminum with the sacrificial protection of zinc, giving the steel better long-term atmospheric corrosion resistance in most environments. Field studies confirm Galvalume provides 2-4× longer service life than standard galvanized steel in equivalent outdoor conditions.
Besides corrosion resistance, Galvalume offers a bright metallic appearance, strong heat reflectivity and heat resistance up to 315°C. It can be formed by bending, corrugating and roll forming, making it a practical and premium material for construction and industrial applications.
For buyers and distributors, Galvalume steel coil is the premium choice when long service life, heat resistance and aesthetic quality are project priorities.
Technical Specifications
Available in various thicknesses, widths and coating options. Common standards include ASTM, JIS, EN and GB/T. Different industries may choose different specifications depending on service life, corrosion requirements and fabrication method.
| Product | Galvalume Steel Coil / GL Coil / Aluzinc Coil |
|---|---|
| Coating | AZ50 – AZ185 (50-185 g/m²) |
| Composition | 55% Aluminum + 43.4% Zinc + 1.6% Silicon |
| Thickness | 0.12 – 4.0 mm |
| Width | 600 – 1500 mm |
| Standard | ASTM A792, EN 10346, JIS G3321, GB/T 55441 |
| Surface | AFP (Anti-Finger Print) / Oiled / Chromate / Bare |
| Steel Grade | DX51D+AZ, DX52D+AZ, S350GD+AZ, S550GD+AZ, G550 |
| Coil ID | 508 mm / 610 mm |
| Coil Weight | 3 – 10 MT (customizable) |
Contact our technical team for specific grade and coating recommendations based on your application environment and processing requirements.
Applications
Thanks to its corrosion resistance, processing flexibility and cost-performance ratio, this product is widely used across construction, manufacturing and industrial sectors.
🏗️ Roofing & Cladding
Premium roofing and wall cladding. 55% Al-Zn provides 2-4× longer life than GI in marine and industrial environments.
☀️ Solar Energy
Solar panel mounting frames, racking systems, and ground screws. Excellent heat resistance up to 315°C continuous service.
🏭 Industrial Building
Pre-engineered building (PEB) roofing, insulated sandwich panel facings, rain gutters, ventilation ducts, and structural decking.
🔧 PPGL Substrate
Base substrate for prepainted Galvalume (PPGL) production on continuous color coating lines. Requires AFP or chromate surface.
Galvalume (GL) vs Galvanized (GI)
Galvalume and Galvanized are both coated steel products but differ in coating composition, performance characteristics and optimal applications.
Galvalume Steel Coil (GL)
Known for superior atmospheric corrosion resistance, heat reflectivity and long roofing life.
Galvanized Steel Coil (GI)
Offers excellent cut-edge protection, superior formability and broad market acceptance.
| Comparison Item | Galvalume Steel Coil (GL) | Galvanized Steel Coil (GI) |
|---|---|---|
| Coating | 55% Al + 43.4% Zn + 1.6% Si alloy | Pure zinc (Z40-Z600) |
| Flat Panel Corrosion | 2-4× better than GI | Good, depends on zinc weight |
| Cut-Edge Protection | Lower — Al does not migrate | Excellent — Zn migrates to cut edges |
| Heat Resistance | Up to 315°C continuous | Up to 230°C |
| Heat Reflectivity | Excellent — reflects solar radiation | Lower than GL |
| Appearance | Bright metallic silver | Traditional zinc spangle |
| Cost | 5-15% higher than GI | More economical |
| Best For | Roofing, solar, heat zones, PPGL substrate | Construction, ducts, tubes, fabrication |
Main Advantages
This product combines durability, processing flexibility and cost-effectiveness for a wide range of applications.
- 2-4× longer corrosion life — Al-Zn alloy provides superior atmospheric corrosion resistance compared to pure zinc coating
- Excellent heat resistance — Continuous service up to 315°C vs 230°C for galvanized — ideal for roofing in hot climates
- Superior heat reflectivity — Reflects solar radiation effectively, reducing building cooling costs and roof temperature
- Premium metallic appearance — Bright, uniform metallic surface that maintains aesthetic quality over decades of outdoor exposure
- Ideal PPGL substrate — The perfect base material for prepainted Galvalume production — maximizes painted steel service life
- Proven 25-50 year roofing life — Decades of field data confirm exceptional service life for metal roofing applications worldwide
Why Choose SunSea Steel?
Choosing the right supplier means more than buying steel. It also means stable quality, export experience, efficient communication and reliable delivery support.
Stable Product Quality
Uniform coating mass, reliable base steel quality and stable surface condition help ensure consistent performance in export orders.
Custom Specification Support
Thickness, width, coating mass, steel grade, surface treatment and packing can be customized according to project requirements.
Professional Export Service
Support for packing, loading, shipping documents and delivery coordination helps customers manage international orders more efficiently.
Fast Response and Quotation
Buyers can quickly get specification confirmation, technical support and quotation feedback for distribution, project procurement and manufacturing use.
Factory Strength and Production Capability
Our production system focuses on coating uniformity, thickness control, clean surface quality and export-standard packing. From raw material selection to final inspection and shipment preparation, every stage is managed to improve product consistency and reduce customer risk.
For buyers, factory capability means more than output volume. It also means communication efficiency, documentation support, shipment coordination and the ability to provide stable product supply over time.
- Stable production planning for export orders
- Support for customized sizes and coating requirements
- Professional handling of packing and shipment preparation
- Inspection and tolerance control before delivery
Quality Control and Inspection
Product quality is one of the key concerns for overseas buyers. Quality should be controlled not only by final visual inspection, but also by process stability, specification verification and export packing inspection.
Surface and Dimension Inspection
Surface condition, width, edge quality and dimensional tolerance are checked before delivery.
Pre-Shipment Quality Control
Packing condition, identification, quantity confirmation and shipment readiness are reviewed before export.
Thickness and Width Verification
Thickness tolerance, width and coil dimensions are checked to ensure the material is suitable for roll forming, profiling and project processing needs.
Coating and Surface Checking
Coating weight requirements and surface appearance are reviewed before packing and shipment.
Packing Inspection
Export packing is examined to ensure moisture-proof protection, steel straps and edge protectors are correctly applied.
Shipment Preparation
Quantity, identification, loading readiness and related documentation are confirmed before export delivery.
Standard Export Seaworthy Packaging
For steel export, correct packaging is extremely important. Even high-quality product can suffer surface damage, moisture exposure or edge deformation if packing is not suitable for sea shipment.
- Inner Moisture Protection: Waterproof kraft paper and plastic film help reduce moisture contact.
- Outer Steel Cover: Additional outer steel sheet gives stronger protection during handling.
- Edge Protection: Edge protectors reduce impact damage during lifting and stacking.
- Steel Strapping: Radial and circumferential straps help keep the coil stable.
- Pallet Support: Wooden or steel pallets can be used according to shipping requirements.
Shipping, Loading and Delivery Solutions
Shipping method depends on order quantity, coil size and destination requirements. Container shipment and break bulk vessel are the most common methods for steel coil export.
Container Shipment
Suitable for regular export orders. Coils packed on pallets and loaded into containers for safe sea transport. FOB/CIF/CFR available.
Break Bulk Vessel Shipment
For large volume orders or oversized coils. Professional lifting, lashing and port handling for bulk steel procurement.
Small to medium orders: container shipment is preferred. Large-scale or project orders: break bulk vessel may be more efficient.
Frequently Asked Questions
What is Galvalume steel coil?
Galvalume (GL) is steel coated with an alloy of 55% aluminum, 43.4% zinc, and 1.6% silicon by hot-dip process. It combines aluminum barrier resistance with zinc sacrificial protection, providing 2-4× longer life than standard galvanized in most environments.
What is the difference between GI and GL?
GI uses pure zinc coating; GL uses 55% Al-Zn alloy. GL has 2-4× better flat panel corrosion resistance but GI has better cut-edge protection. GL resists heat to 315°C vs 230°C for GI.
What does AZ150 mean?
AZ150 means 150 g/m² total Al-Zn coating on both sides (75 g/m² per side). This is the standard coating for roofing and most GL applications globally.
What is AFP surface treatment?
AFP (Anti-Finger Print) is a clear chromate-free coating applied to GL surface. It prevents fingerprint marking during handling and provides additional corrosion protection.
Can Galvalume be used for roofing?
Yes. Galvalume is one of the most popular roofing materials globally because of its heat reflectivity, corrosion resistance and long outdoor service life (25-50 years).
What is the MOQ?
25 MT per specification for full containers. Mixed containers: 5 MT/spec minimum with 25 MT total.
Can you provide customized specifications?
Yes. Thickness, width, coating weight, steel grade, surface treatment and export packaging can all be customized.
Looking for a Reliable Galvalume Steel Coil Supplier?
Contact us for GL coil pricing, specifications, AFP treatment, export packing and shipping. Factory direct supply worldwide.
✉️ Send Email 💬 Chat on WhatsApp