When sourcing galvanized steel sheets for construction, manufacturing, or infrastructure projects, understanding the standard SGCC (a common JIS G 3302 grade) specifications is essential. SGCC refers to a commercial quality hot-dip galvanized steel sheet primarily used in applications where corrosion resistance and formability are key. Unlike higher-strength grades like SGCH or SGC340, SGCC is designed for general use and is often selected for its balance of cost, durability, and ease of fabrication.
One of the most frequently asked questions is about the standard thickness and width of SGCC galvanized sheets. In practice, thickness typically ranges from 0.2 mm to 3.2 mm, with common increments such as 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, and 2.0 mm. These values align with both industrial demand and roll-forming compatibility. For width, the standard coil and sheet sizes vary between 600 mm and 1250 mm, with 914 mm, 1000 mm, and 1219 mm (48 inches) being the most widely available. Custom slitting services allow for narrower strips, which is particularly useful in HVAC ducting, roofing panel production, and metal furniture manufacturing.
Cut-to-size options are increasingly popular among fabricators and contractors who aim to reduce on-site waste and labor. Many suppliers, including Asia Metal Ltd, offer precision shearing and slitting to meet exact dimensions—whether you need 1000 mm x 2000 mm panels for cladding or 300 mm x 500 mm blanks for stamping. This flexibility supports just-in-time manufacturing and improves overall project efficiency. Always confirm tolerance levels (e.g., ±0.5 mm for length and width) when placing orders to avoid fit issues during installation.
The zinc coating on SGCC sheets is another critical factor. According to JIS G 3302, the standard coating mass is Z12 to Z27, representing 120 g/m² to 275 g/m² of zinc on both sides. For example, a Z18 coating (180 g/m²) offers adequate protection in moderate environments, while Z27 is better suited for coastal or high-humidity regions. The coating not only prevents rust but also enhances paint adhesion, making SGCC ideal for pre-painted metal (PPM) applications. For more detailed information on galvanization processes, see the Wikipedia entry on galvanization.
Typical SGCC galvanized steel coils and precision-cut panels ready for fabrication.
Surface finish also plays a role in application suitability. SGCC is commonly available in two surface conditions: regular spangle and minimized spangle. Regular spangle has a visible crystalline pattern and is often used in non-visible structural parts. Minimized spangle, with its smoother appearance, is preferred for applications requiring painting or aesthetic finishes, such as metal roofing, garage doors, and interior panels.
Mechanical properties are moderate but sufficient for most non-structural uses. Typical yield strength ranges from 140 MPa to 280 MPa, with tensile strength between 270 MPa and 410 MPa. Elongation is generally above 25%, allowing for bending, roll forming, and shallow drawing without cracking. However, SGCC is not recommended for high-stress environments—grades like SGC340 or SGC400 are better choices when structural integrity is paramount.
Another advantage of SGCC galvanized steel is its compatibility with various secondary processes. It can be easily welded (with proper ventilation due to zinc fumes), painted, powder-coated, and even laser cut with appropriate settings. For fabricators, this versatility reduces the need for material substitution across different production stages.
When selecting a supplier, reliability and quality control matter. Asia Metal Ltd stands out by offering full mill test certificates (MTCs), third-party inspection support, and 12-hour customer response times—ensuring that every batch meets JIS, ASTM, or EN standards. Their advanced slitting and shearing lines enable tight tolerances and fast turnaround, even for custom-sized orders.
Packaging is often overlooked but crucial for long-distance shipping. Standard export packaging includes plastic film wrapping, edge protectors, steel strapping, and wooden pallets to prevent moisture damage and mechanical deformation during transit. Some suppliers also offer moisture-proof paper or VCI (Vapor Corrosion Inhibitor) film for extra protection—especially valuable in humid or maritime environments.
In terms of application, SGCC galvanized sheets are found in:
- Metal roofing and wall cladding systems
- HVAC ducts and ventilation components
- Electrical enclosures and switchgear cabinets
- Fencing, guardrails, and signage
- Metal furniture and storage systems
- Agricultural equipment and greenhouse frames
For projects requiring lightweight yet durable materials, SGCC offers a compelling value proposition. Its combination of corrosion resistance, formability, and cost-effectiveness makes it a go-to choice across multiple industries. Whether you're sourcing full coils or need cut-to-size sheets, partnering with a supplier that guarantees consistent quality and on-time delivery is just as important as the material specs themselves.
Always request a sample before bulk ordering, especially when working with new suppliers. This allows you to verify surface quality, thickness accuracy, and edge condition. Additionally, confirm the availability of documentation such as ISO certifications, material traceability reports, and compliance with RoHS or REACH regulations if needed.
In summary, SGCC galvanized steel remains a cornerstone material in modern metal fabrication. With standardized thickness and width options, excellent zinc protection, and broad process compatibility, it continues to serve diverse industrial needs. By understanding the specs and choosing a trusted supplier, you ensure both performance and longevity in your final products.