Understanding the ASTM A792 galvalume steel coil specification is critical for procurement managers in the metal roofing, construction, and automotive industries. This international standard governs the composition, mechanical properties, and coating requirements for steel coils coated with aluminum-zinc alloy (55% Al, 43.5% Zn, 1.5% Si). As a leading galvalume supplier China, ChinaCNU Steel manufactures these coils in our Qingdao factory with ISO 9001:2015 certification and over 15 years of export experience. This guide covers everything from coating designations like AZ150 to ordering parameters, ensuring you make informed bulk purchasing decisions with MOQ 25 tons.
What Is the ASTM A792 Galvalume Steel Coil Specification?
The ASTM A792 standard, last updated in 2026, specifies the requirements for steel sheet, metallic-coated by the hot-dip process, with a zinc-aluminum alloy coating. This aluzinc steel coil offers superior corrosion resistance compared to traditional galvanized steel, up to 2-4 times longer service life in many environments. The specification covers multiple coating weights (AZ30, AZ50, AZ90, AZ150, AZ185, AZ200) and structural grades (CS Type A/B/C, SS Grade 33/37/40, HSLAS Grade 45/50/55/60/65/70).
Zinc Coating Grade Comparison – Corrosion Protection Level
Reference: ISO 1461 / ASTM A653 | ChinaCNU Steel Technical Dept.
For metal roofing coil applications, the AZ150 coating designation (0.50 oz/ft² total coating weight on both sides) is the most common. Our Qingdao factory produces coils with a thickness range of 0.12 mm to 2.5 mm and widths from 600 mm to 1500 mm. The base metal is cold-rolled steel (CR) or hot-rolled pickled and oiled (HRPO), ensuring excellent formability for roll-forming and bending operations.
Key Mechanical Properties per ASTM A792
Structural steel grades (SS) require minimum yield strengths from 33 ksi to 80 ksi. For example, SS Grade 50 demands 50 ksi yield and 60 ksi tensile strength. Our galvalume supplier China capabilities include full tensile testing per ASTM A370 and coating weight verification via ASTM A90/A90M. Every coil from our factory ships with a mill test certificate (MTC) confirming compliance.
Coating Designations: AZ30 to AZ200 Explained
The coating weight designation (e.g., AZ150 galvalume) indicates the total coating mass on both surfaces in g/m². A higher number means thicker coating and longer corrosion protection. Below is a comparison table of common designations:
| Coating Designation | Total Coating Weight (g/m²) | Typical Applications | Relative Corrosion Resistance |
|---|---|---|---|
| AZ30 | 30 | Light indoor applications, ductwork | Low |
| AZ50 | 50 | General roofing, gutters | Moderate |
| AZ90 | 90 | Agricultural buildings, wall panels | Good |
| AZ150 | 150 | Premium metal roofing, industrial cladding | Excellent |
| AZ185 | 185 | Coastal environments, marine structures | Superior |
| AZ200 | 200 | Extreme corrosion zones, chemical plants | Maximum |
Our Qingdao factory stocks AZ150 as a standard product, with FOB pricing starting at $780/ton for bulk orders of 25 tons or more. For aluzinc steel coil with anti-fingerprint coating or pre-painting, we offer additional surface treatments that meet ASTM A792 Appendix X1 requirements.
Grades and Applications for ASTM A792 Coils
ASTM A792 categorizes coils into commercial steel (CS) for simple forming, structural steel (SS) for load-bearing applications, and high-strength low-alloy (HSLAS) for weight reduction. Our galvalume supplier China network exports these grades to over 50 countries, including the USA, Canada, UAE, and Southeast Asia.
Commercial Steel (CS) Types A, B, C
CS Type A is used for moderate forming; Type B for tight bends; Type C for deep drawing. These are ideal for metal roofing coil accessories like flashings and ridge caps. The specification requires no minimum yield point, making them highly ductile.
Structural Steel (SS) Grades 33, 37, 40, 50, 80
SS Grade 50 is the most popular for standing seam roofing. It offers 50 ksi minimum yield strength and excellent weldability. Our factory can supply SS Grade 50 with AZ150 coating in widths up to 1219 mm, meeting both ASTM A792 and EN 10142 standards for global projects.
HSLAS Grades 45-70 (Class 1 & 2)
High-strength low-alloy grades reduce material weight by 15-20% while maintaining strength. Class 1 has improved formability; Class 2 offers higher strength. These are specified for pre-engineered buildings and structural purlins.
Why Choose ChinaCNU Steel as Your Galvalume Supplier China?
Our Qingdao factory operates three continuous hot-dip coating lines with annual capacity of 600,000 tons. We are ISO 9001, ISO 14001, and SGS certified. Since 2010, we have exported ASTM A792 galvalume steel coil to 80+ countries with zero quality claims in the last 5 years. Our galvalume supplier China advantages include:
- FOB Pricing – Competitive rates from Tianjin Xingang port, with free loading for MOQ 25 tons
- Stock Availability – 10,000 tons of AZ150 in standard sizes ready for immediate shipment
- Custom Processing – Slitting, cutting to length, embossing, and anti-fingerprint coating
- Third-Party Inspection – SGS, BV, or Intertek testing at your request
- 15+ Years Export – Dedicated English-speaking sales team for seamless logistics
Our aluzinc steel coil passes ASTM A792 bend tests, salt spray tests (ASTM B117), and coating adhesion tests (ASTM D3359). We provide a 20-year corrosion warranty on AZ150 for standard roofing applications.
Ordering Guide: How to Specify ASTM A792 Coils
When ordering ASTM A792 galvalume steel coil specification products, include these parameters:
- Base Metal – Cold-rolled (CR) or hot-rolled (HR)
- Grade – CS Type B, SS Grade 50, or HSLAS Grade 55
- Coating Designation – AZ150, AZ90, etc.
- Surface Treatment – Chemical treatment, oiled, dry, anti-fingerprint
- Dimensions – Thickness (mm), width (mm), coil ID (508mm or 610mm)
- Quantity – Minimum 25 tons for standard FOB pricing
- Certification – Mill test certificate required
For example: ASTM A792 SS Grade 50 AZ150, CR, 0.5mm x 1200mm, coil ID 508mm, chemical treated, oiled, 50 tons. Our team provides a proforma invoice within 24 hours with FOB Tianjin pricing.
Frequently Asked Questions (FAQ)
1. What is the difference between ASTM A792 and A653?
ASTM A653 covers hot-dip galvanized (zinc) coatings, while ASTM A792 specifically addresses aluminum-zinc alloy (galvalume) coatings. A792 offers 2-4x better corrosion resistance and higher temperature reflectivity, making it preferred for metal roofing in coastal or industrial environments.
2. Can AZ150 galvalume be painted or powder coated?
Yes. Our Qingdao factory supplies pre-painted coils with polyester, PVDF, or SMP coatings per ASTM A755. For field painting, the surface should be cleaned and primed with a zinc-rich primer. Anti-fingerprint treatment is also available for exposed applications.
3. What is the minimum order quantity (MOQ) for FOB pricing?
Our standard MOQ is 25 metric tons per specification. For smaller quantities (10 tons+), we offer CFR/CIF pricing with slightly higher unit costs. Contact our sales team for trial orders or mixed container options.
4. How does AZ150 compare to AZ90 for roofing?
AZ150 (150 g/m² coating weight) provides approximately 40% longer corrosion protection than AZ90 (90 g/m²) in identical environments. For residential metal roofing with a 30+ year design life, AZ150 is the industry standard. AZ90 is suitable for agricultural sheds or temporary structures.
5. What certifications do ChinaCNU Steel provide with each coil?
Every shipment includes: Mill Test Certificate (MTC) per ASTM A792, Certificate of Compliance, packing list, and bill of lading. Third-party inspection reports from SGS, BV, or Intertek are available at an additional cost. Our ISO 9001:2015 certification covers all production processes.
MOQ 25 tons | FOB Tianjin | ISO Certified | 15+ Years Export
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