Galvanized steel plate and sheet refers to carbon steel that has been coated with a protective layer of zinc through a hot-dip or electro-galvanizing process. The zinc coating forms a metallurgical bond with the base steel, providing excellent corrosion resistance and extending service life in harsh environments. At YS STEEL, we produce both structural-grade and commercial-grade galvanized products according to international standards such as ASTM A653, EN 10346, JIS G3302, and GB/T 2518.
The term “plate” generally refers to flat products with a thickness of 6 mm or greater, while “sheet” refers to thinner products below 6 mm. However, in many markets the two terms are used interchangeably. YS STEEL covers both categories with cold rolled substrate from 0.12 mm to 3.0 mm and hot rolled substrate from 1.5 mm to 25 mm, giving customers a single source for everything from thin appliance panels to heavy structural plates.
YS STEEL offers the following standard specifications for Galvanized Steel Plates and Sheets. Custom dimensions and coating weights are available upon request.
| Specification | Range | Common Applications |
|---|---|---|
| Thickness (cold rolled) | 0.12 mm – 3.0 mm | Roofing, cladding, appliances, automotive body panels |
| Thickness (hot rolled) | 1.5 mm – 25 mm | Structural beams, base plates, heavy equipment |
| Width | 600 mm – 2,000 mm | General fabrication, roll forming, stamping |
| Length | 1,000 mm – 12,000 mm | Cut-to-length sheets, laser cutting, press brake |
| Zinc coating (hot-dip) | Z40 – Z600 g/m² | Outdoor structures, marine environments, highway guardrails |
| Zinc coating (electro) | 20 – 200 g/m² | Automotive exposed panels, electronic enclosures |
| Surface finish | Regular, minimized, zero spangle | Painting, powder coating, visible appearance |
The table below shows typical mechanical properties for common galvanized steel grades supplied by YS STEEL. Values are for reference and may vary according to the specific standard and heat treatment.
| Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Typical Use |
|---|---|---|---|---|
| DX51D / SGCC | 140 – 280 | 270 – 400 | ≥ 26 | General forming, roofing, ducting |
| DX52D / SGCD1 | 140 – 300 | 270 – 420 | ≥ 24 | Deep drawing, appliances, panels |
| DX53D / SGCD2 | 140 – 260 | 270 – 380 | ≥ 30 | Extra deep drawing, automotive parts |
| S220GD | ≥ 220 | ≥ 300 | ≥ 20 | Structural sections, purlins |
| S350GD | ≥ 350 | ≥ 420 | ≥ 17 | High-strength framing, racks |
| S550GD | ≥ 550 | ≥ 560 | ≥ 10 | Heavy structural, automotive chassis |
YS STEEL provides multiple coating types to suit different fabrication methods and end-use environments. Hot-dip galvanized products are available with regular, minimized, and zero spangle finishes. Electro-galvanized products offer a smoother surface for critical painted applications. The table below summarizes the main coating and surface treatment options.
| Coating Type | Coating Weight Range | Surface Characteristics | Recommended Use |
|---|---|---|---|
| Hot-dip galvanized, regular spangle | Z40 – Z600 g/m² | Visible zinc flower pattern, good adhesion | General outdoor structures, guardrails, ducting |
| Hot-dip galvanized, minimized spangle | Z60 – Z350 g/m² | Fine, uniform surface, better paint base | Architectural panels, roof cladding, signage |
| Hot-dip galvanized, zero spangle | Z60 – Z275 g/m² | Very smooth, no visible pattern | High-end painted surfaces, appliances |
| Electro-galvanized | 20 – 200 g/m² | Extremely uniform, excellent surface quality | Automotive exposed parts, electronic enclosures |
| Galvannealed | Z45 – Z350 g/m² | Iron-zinc alloy layer, matte gray finish | Welded assemblies, automotive body panels |
Surface treatments such as chromating, oiling, and anti-fingerprint coating can be applied to prevent white rust during storage and transit. Chromated surfaces provide excellent corrosion protection but may require cleaning before painting. Oiled surfaces are easy to weld and form but must be cleaned before coating. Anti-fingerprint treatments are ideal for visible surfaces that will be handled frequently.
YS STEEL uses continuous hot-dip galvanizing lines with in-line annealing furnaces. Cold rolled or hot rolled base coils are cleaned, annealed, and immersed in a molten zinc bath at approximately 450–460°C. The coating thickness is controlled precisely by air knives. For electro-galvanized products, zinc is deposited electrolytically on a cold rolled substrate, which allows thinner and more uniform coatings.
After galvanizing, the steel passes through skin-pass rolling and tension leveling to improve surface quality and flatness. Customers can choose from chromated, oiled, or anti-fingerprint surface treatments depending on forming and painting requirements. Every coil is inspected for coating weight, surface defects, and dimensional accuracy before release. YS STEEL uses X-ray fluorescence and magnetic induction gauges to verify zinc coating thickness, and salt spray testing is available for corrosion resistance qualification.
Different regions use different designations for Galvanized Steel Plates and Sheets. YS STEEL maintains a cross-reference system to help customers specify the correct grade regardless of the standard. The table below lists common equivalent grades.
| Standard | Commercial Quality | Deep Drawing Quality | Structural Quality |
|---|---|---|---|
| ASTM A653 | CS Type A, B, C | FS Type A, B | SS Grade 33–80 |
| EN 10346 | DX51D | DX52D, DX53D, DX54D | S220GD – S550GD |
| JIS G3302 | SGCC | SGCD1, SGCD2, SGCD3 | SGH340, SGH400, SGH440 |
| GB/T 2518 | DX51D | DX52D, DX53D | S220GD – S550GD |
| AS 1397 | G250 | G300, G350 | G450, G500, G550 |
YS STEEL can supply to any of these standards and provide a certificate of compliance with each shipment. For mixed orders involving multiple specifications, each bundle is clearly marked with the grade, coating weight, dimensions, heat number, and standard.
Galvanized steel plate and sheet serves a wide range of industries. Its combination of corrosion resistance, formability, weldability, and cost-effectiveness makes it a preferred material for both structural and non-structural components.
In construction, hot-dip Galvanized Steel Plates and Sheets are widely used for metal roofing because it withstands decades of rain, snow, and UV exposure. In automotive manufacturing, galvanized sheet metal prevents corrosion perforation in doors, hoods, and quarter panels. In appliances, the smooth surface and consistent thickness of galvanized steel allow high-speed stamping and precise assembly.
YS STEEL has built a reputation for consistent coating adhesion, precise thickness tolerances, and on-time delivery. Every coil and sheet is traceable to its mill certificate, and third-party inspection is available through SGS, BV, or Intertek. We offer small trial orders, mixed container loading, and custom packaging for export markets.
Coils from YS STEEL are wrapped in anti-rust paper, covered with PVC film, and secured with steel strapping. Cut-to-length sheets are stacked on wooden pallets with edge protectors and corner guards. For export, all packages are fumigated or heat-treated according to ISPM 15 requirements. We load 20-foot and 40-foot containers with a maximum coil weight of 12 metric tons. Each package carries a durable metal or waterproof label showing the customer order number, grade, dimensions, coating weight, and gross/net weight.
Before shipment, YS STEEL conducts the following inspections on galvanized steel plate and sheet:
All test results are recorded in the mill test certificate and can be provided digitally before shipment. Any non-conforming material is quarantined and replaced before loading.
Q: What is the difference between hot-dip galvanized and electro-galvanized steel plate and sheet?
A: Hot-dip galvanizing immerses the steel in molten zinc, producing a thicker zinc layer that typically ranges from 40 to 600 g/m². This creates a strong metallurgical bond and superior outdoor corrosion resistance. Electro-galvanizing deposits zinc through an electrolytic process, resulting in a thinner, more uniform coating between 20 and 200 g/m². Electro-galvanized material offers better surface smoothness and is often preferred for painted automotive panels, while hot-dip galvanized steel is the standard choice for roofing, structural components, and outdoor equipment.
Q: How do I choose the correct zinc coating weight for my project?
A: The required zinc coating weight depends on the expected corrosion exposure and service life. For indoor or mild environments, a Z120–Z180 coating is usually sufficient. For outdoor rural or suburban applications, Z275 is common. Coastal and industrial environments with high humidity or airborne salts often require Z350–Z600. YS STEEL technical engineers can help match the coating weight to your specific project conditions, taking into account factors such as rainfall, temperature swings, and exposure to chemicals.
Q: Can galvanized steel plate and sheet be welded without damaging the zinc coating?
A: Yes, galvanized steel can be welded using common methods such as MIG, TIG, and resistance welding. However, the zinc coating near the weld zone will vaporize at high temperatures, so proper ventilation and personal protective equipment are necessary because zinc oxide fumes can be hazardous. After welding, the affected area should be cleaned and coated with a zinc-rich paint or cold galvanizing compound to restore corrosion protection. YS STEEL recommends selecting minimized spangle or zero spangle products for smoother weld beads.
Q: What is spangle, and does it affect the performance of Galvanized Steel Plates and Sheets?
A: Spangle refers to the visible crystalline pattern that forms on the surface during the solidification of the zinc coating. Regular spangle has a larger, flower-like appearance, while minimized and zero spangle have finer or no visible patterns. Spangle does not significantly affect corrosion resistance in most environments, but it does influence surface roughness and paint adhesion. For high-quality painted surfaces or visible architectural panels, minimized or zero spangle is generally recommended. YS STEEL offers all three spangle options to meet different surface quality requirements.
Q: How should galvanized steel plate and sheet be stored to prevent wet storage stain?
A: Galvanized coils and sheets should be stored indoors in a dry, well-ventilated area. If outdoor storage is unavoidable, keep the material off the ground on wooden dunnage, cover it with breathable tarps, and ensure air circulation to prevent condensation. Avoid direct contact with wet wood, cement floors, or other materials that can trap moisture. If coils or bundles arrive wet, separate them and dry them immediately. Wet storage stain, or white rust, appears as a white powdery deposit and can reduce the protective life of the zinc layer. Light white rust can be removed with a stiff brush, but heavy oxidation may require chemical treatment or recoating.
