Galvanized Steel Sheet DX51D with Z30-Z40 Zinc Coating Cold Rolled Mid Hard Regular Spangle

Galvanized Steel Sheets are essential materials in modern construction and manufacturing, valued for their excellent corrosion resistance, formability, and durability. Manufactured by Wuxi Sylaith Special Steel Co., Ltd. , these high-quality GI sheets feature a Z30-Z40 zinc coating on a cold-rolled steel base, ensuring reliable performance in various applications.

Our Prime Galvanized Sheets are available in grades DX51D, DX52D, SGCC, and SPCC, meeting international standards including AISI, ASTM, JIS, DIN, GB, and EN. With thickness ranging from 0.21mm to 0.50mm, mid-hard hardness, and regular spangle finish, these sheets deliver the perfect balance of strength and formability for roofing, construction, pipe making, and general fabrication.

Applications

The versatility of Sylaith Galvanized Steel Sheets makes them suitable for a wide range of industries:

1. Roofing & Construction

• Corrugated roofing sheets

• Wall cladding and siding

• Building panels

• Ceiling tiles

2. Pipe & Tube Making

• Welded pipes and tubes

• Conduits

• HVAC ductwork

3. Container Manufacturing

• Shipping containers

• Storage tanks

• Industrial containers

4. General Fabrication

• Small tools and hardware

• Fencing and gates

• Electrical cabinets

• Automotive parts

5. Corrugated Sheets

• Wave-shaped roofing panels

• Industrial shelter covers

Working Principle: How Galvanized Steel Sheets Are Made

Galvanized steel sheets are produced through a combination of cold rolling and hot-dip galvanizing processes.

Step 1: Cold Rolling Base

High-quality steel strips are cold rolled to achieve precise thickness (0.21-0.50mm) with tight tolerances (±1%) and a smooth surface finish.

Step 2: Surface Cleaning

The cold rolled strip is thoroughly cleaned through:

• Degreasing: Removes rolling oils

• Pickling: Removes iron oxides and scale

• Fluxing: Prepares surface for optimal zinc adhesion

Step 3: Hot-Dip Galvanizing

The cleaned strip passes through a bath of molten zinc at approximately 450°C. A metallurgical bond forms between the steel and zinc, creating a corrosion-resistant layer with Z30-Z40 coating.

Step 4: Cooling & Spangle Formation

The coated strip is cooled, allowing zinc crystals (spangles) to form. Regular spangle provides a uniform, aesthetic appearance.

Step 5: Skin Pass (Temper Rolling)

A light cold rolling pass (skin pass) is applied to:

• Improve surface flatness

• Enhance mechanical properties

• Prevent yield point elongation

Step 6: Surface Treatment

Optional treatments include:

• Chromated: Enhanced corrosion resistance

• Oiled/Non-oiled: Rust protection during transport

• Anti-fingerprint: For visible applications

Step 7: Quality Inspection

Every coil undergoes rigorous testing:

• Coating weight verification (Z30-Z40)

• Thickness measurement (±1% tolerance)

• Surface quality assessment

• Mechanical property testing

FAQ (Frequently Asked Questions)

Q1: What is the difference between DX51D and SGCC?

A:

• DX51D: European standard (EN 10346) for hot-dip galvanized steel, widely used internationally

• SGCC: Japanese standard (JIS G3302) for hot-dip galvanized steel, common in Asia

Both offer excellent corrosion resistance and formability. We can supply either based on your requirements.

Q2: What is Z30-Z40 coating?

A: Z30-Z40 refers to the zinc coating weight of 30-40 g/m² (total both sides). This provides good corrosion resistance for general applications. Higher coating weights (up to Z275) are available for more corrosive environments.

Q3: What does "Mid Hard" mean?

A: Mid Hard indicates an optimal balance between strength and formability:

• Hard enough for structural integrity

• Soft enough for bending and forming

• Ideal for general fabrication and roofing applications

Q4: What is regular spangle?

A: Regular spangle refers to the visible zinc crystal pattern on the surface. It provides a uniform, aesthetic appearance commonly preferred for visible applications like roofing and wall panels.

Q5: What thickness do you offer?

A: Standard thickness range is 0.21mm to 0.50mm. We can also supply thicknesses from 0.3mm to 3.0mm upon request.

Q6: Can you customize the length?

A: Yes, we offer custom lengths based on customer requirements. Please provide your specifications for a custom quotation.

Q7: What certifications do your products have?

A: Our products are ISO 9001 certified and comply with ASTM, AISI, JIS, DIN, GB, and EN standards.

Q8: What is your MOQ?

A: MOQ is flexible — we accept orders starting from 1 ton. Sample orders are welcome.

Q9: Do you provide processing services?

A: Yes, we offer welding, punching, decoiling, bending, and cutting services to meet your specific requirements.

Q10: What is the difference between oiled and non-oiled surface?

A:

• Oiled: Thin protective oil layer to prevent white rust during storage and transport

• Non-oiled: No oil coating, suitable for immediate painting or processing

Q11: Can you provide samples?

A: Yes, sample orders are welcome. Please contact us to discuss sample requirements.

Q12: Are these sheets suitable for outdoor use?

A: Yes, the Z30-Z40 zinc coating provides good corrosion resistance for outdoor applications like roofing and fencing. For harsh environments, higher coating weights (Z180-Z275) are recommended.

Wuxi Sylaith Special Steel Co., Ltd. is located in Wuxi, Jiangsu Province, China — one of the largest steel distribution centers in East China. Since its establishment, the company has focused on supplying premium-quality steel materials and providing reliable one-stop steel solutions for customers worldwide.

With a warehouse area of more than 20,000 square meters and over 20,000 tons of ready stock inventory, Sylaith has become a trusted supplier for clients in construction, manufacturing, machinery, shipbuilding, energy, and infrastructure industries.

Our products comply with multiple international standards including ASTM, AISI, JIS, DIN, EN, GB, and BS standards, ensuring stable quality and excellent performance for global markets.

Main Products

• Stainless Steel Sheets & Coils
• 304 / 316 Stainless Steel Coil
• Wear Resistant Steel Plates
• Carbon Steel Sheets & Plates
• Galvanized Steel Coils
• Copper Coils & Copper Sheets
• Aluminum Sheets & Coils
• Rectangular Tubes & Steel Pipes
• Customized Steel Processing Products

Industries We Serve

Our steel products are widely used in:

• Construction & Bridge Engineering
• Steel Structure Projects
• Offshore & Marine Engineering
• Machinery Manufacturing
• Energy & Power Plants
• Metallurgical Equipment
• Automotive & Industrial Fabrication