May 30, 2026 · 6 min read

JIS G3321 Galvalume Steel Sheet – Premium Aluzinc Coil for Roofing

Review certificate records, scope and current status. Confirm order-specific documentation and inspection requirements with the export team.

JIS G3321 galvalume steel sheet steel coil - ChinaCNU Steel

What Is JIS G3321 Galvalume Steel Sheet?

JIS G3321 defines the specifications for hot-dip 55% aluminum-zinc alloy-coated steel sheet and coil. This coating, often called aluzinc, provides superior corrosion resistance compared to traditional hot-dip galvanized steel. The standard covers multiple grades, including SGLCC, SGLCD, and SGLCE, each with specific mechanical properties for bending, forming, and structural use. The AZ150 designation refers to the coating weight of 150 g/m² (total both sides), which is the most common specification for exterior building materials like roofing and siding. As a galvalume supplier China, we ensure every coil meets the chemical composition limits for aluminum, zinc, and silicon, guaranteeing consistent performance in aggressive environments.

Key Benefits of AZ150 Galvalume Coating

The 55% aluminum-zinc coating creates a barrier that is 2–4 times more corrosion-resistant than standard galvanized steel. This makes JIS G3321 galvalume steel sheet ideal for agricultural buildings, industrial warehouses, and residential roofing in coastal or industrial zones. The coating also offers excellent heat reflectivity, reducing cooling costs in warm climates. Our aluzinc steel coil is produced with tight thickness tolerances (±0.02 mm for 0.3–0.8 mm thickness) and superior surface quality, ensuring no spangle or minimal spangle finishes as required by the standard.

JIS G3321 Grades and Mechanical Properties

Understanding the grade designation is critical when selecting the right JIS G3321 galvalume steel sheet for your project. Below is a comparison table of common grades and their typical applications:

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)	Typical Application
SGLCC	270–500	≥ 380	≥ 18	General forming, roofing, siding
SGLCD	270–440	≥ 360	≥ 22	Deep drawing, complex profiles
SGLCE	270–410	≥ 340	≥ 26	Severe forming, automotive parts
SGLCC AZ150	270–500	≥ 380	≥ 18	Metal roofing coil, industrial panels

For most construction applications, SGLCC with AZ150 coating is the standard choice. Our factory produces all grades with full traceability, and each coil is tested for coating weight, adhesion, and bend performance per JIS G3321:2019. We also offer custom slitting to width, so you receive exactly the metal roofing coil width you need—from 600 mm to 1250 mm.

Why Choose ChinaCNU Steel as Your Galvalume Supplier China?

Certificate records — Review the certificate holder, scope and current verification status. Confirm the documents applicable to your order.

Quality Control and Testing

Before shipment, each batch of aluzinc steel coil undergoes rigorous testing: coating weight analysis by X-ray fluorescence, T-bend adhesion tests, and salt spray corrosion testing per ASTM B117. Our in-house lab is accredited to perform these tests, and we provide mill test certificates with every order. This level of quality assurance is why architects and engineers specify our JIS G3321 galvalume steel sheet for critical structures like airport hangars, cold storage facilities, and solar panel mounting systems.

Applications of JIS G3321 Galvalume Steel Sheet in 2026

The construction industry continues to demand materials that offer long service life with minimal maintenance. In 2026, JIS G3321 galvalume steel sheet is the material of choice for:

Metal roofing and wall cladding – AZ150 coating provides 25+ year corrosion protection in most environments.
Agricultural buildings – Barns, poultry houses, and grain silos benefit from the heat reflectivity and chemical resistance.
Industrial insulation panels – Sandwich panels with PIR or EPS cores rely on galvalume facing for durability.
Automotive components – SGLCD and SGLCE grades are used in exhaust systems and heat shields.
Solar energy structures – Ground-mount and roof-mount racking systems use aluzinc steel for corrosion resistance.

Our clients in Southeast Asia, Africa, and the Middle East particularly value the combination of FOB pricing and high corrosion resistance in humid and salty environments. We also supply prepainted versions (color-coated) for architectural aesthetics, all based on the same JIS G3321 galvalume base substrate.

FOB Pricing and MOQ for Galvalume Coils

We offer competitive FOB Tianjin pricing for JIS G3321 galvalume steel sheet. Prices vary by grade, coating weight, thickness, and order quantity. Our standard MOQ is 25 tons per size and specification, which allows us to maintain efficient production and pass cost savings to you. For larger orders—100 tons or more—we can offer additional volume discounts. Typical thickness range is 0.2 mm to 2.0 mm, with width up to 1250 mm. All coils are packed for sea freight with waterproof paper, steel strapping, and edge protection.

How to Order

Simply send us your required dimensions (thickness, width, coil ID), grade, coating weight (AZ150 or other), and quantity. We will respond within 24 hours with a confirmed FOB price, production lead time (usually 15–20 days), and shipping schedule. Our export team handles all documentation, including bill of lading, packing list, and certificate of origin.

Frequently Asked Questions

Q1: What is the difference between JIS G3321 and ASTM A792?

A: JIS G3321 is the Japanese standard for 55% Al-Zn coated steel, while ASTM A792 is the US equivalent. Both specify similar coating composition and mechanical properties, but JIS G3321 includes more grade options for forming (SGLCD, SGLCE). Our JIS G3321 galvalume steel sheet meets both standards in most cases.

Q2: Can you supply JIS G3321 galvalume sheet with AZ150 coating in 0.5 mm thickness?

A: Yes. 0.5 mm thickness with AZ150 coating is our most popular specification for metal roofing coil. We supply it in widths from 900 mm to 1250 mm, slit to your exact requirement. MOQ is 25 tons per width.

Q3: How does the AZ150 coating compare to AZ100 or AZ200?

A: AZ150 (150 g/m² total) offers a balanced combination of corrosion resistance and formability. AZ100 is lighter and less expensive but provides shorter service life. AZ200 offers maximum corrosion protection for extreme environments. For most roofing applications, AZ150 is the industry standard.

Q4: What is the typical lead time for FOB orders from Qingdao?

A: For standard grades and sizes, production takes 15–20 working days after confirmation. Sea freight to major ports (e.g., Singapore, Dubai, Lagos) takes 15–30 days. We can also arrange express delivery for sample orders of 1–2 tons.

Q5: Do you provide third-party inspection certificates?