SGCC vs SECC: Differences, Material Properties, Applications & How to Choose

What Are SGCC and SECC? (Quick Overview)

SGCC steel (Hot-Dip Galvanized Steel) is a zinc-coated steel sheet created through a hot-dip galvanizing process applied to SPCC. Its thick coating provides robust corrosion protection, making it ideal for outdoor and structural applications.

SECC (Electro-Galvanized Steel) is produced via an electrolytic zinc deposition method on SPCC steel. It has a thin, uniform zinc layer, excellent paint adhesion, and high dimensional accuracy, which is perfect for indoor electronics and precision parts.

These two materials are frequently compared because they are both based on SPCC steel and offer corrosion resistance, but differ in coating thickness, durability, and suitable applications.

Key industries that commonly use SGCC material and SECC include construction, automotive, HVAC, electronics, and household appliances.

Manufacturing Processes: Hot-Dip vs Electro-Galvanization

SGCC Manufacturing Process (Hot-Dip Galvanizing)

• Zinc bath immersion process: Steel sheets made from SPCC material are immersed in molten zinc, forming a strong metallurgical bond.
• Coating formation & typical thickness: A thick zinc layer develops along with an alloy layer. Typical coating thickness ranges from 40–200 g/m² per side.
• Cooling process, alloy layer, spangles: Controlled cooling creates an optional spangle pattern on the surface, which does not affect corrosion resistance.
• Standards: Commonly aligned with JIS G3302, EN 10346 equivalents.

   

This process ensures SGCC steel is highly corrosion-resistant, suitable for structural and outdoor use, with long-lasting durability.

SECC Manufacturing Process (Electro-Galvanizing)

• Electrolytic zinc deposition method: A thin zinc layer is deposited onto SPCC material using electric current in a zinc solution.
• Coating uniformity & thin-layer characteristics: Produces a smooth, uniform surface ideal for decorative and precision applications.
• Typical zinc coating weight: 5–30 g/m² per side.
• Standards: JIS G3313, EN 10152 equivalents.

   

This method produces SECC steel with high dimensional stability, excellent paintability, and suitability for electronics and indoor applications.

Key Manufacturing Differences

The table highlights why SGCC material is preferred for outdoor and structural projects, while SECC is ideal for precise indoor components.

Material Properties Comparison (Chemical, Mechanical & Physical)

Chemical Composition (SGCC vs SECC)

SGCC steel: Base SPCC material with zinc-aluminum-magnesium or zinc-lead alloy coating.
SECC: Base SPCC steel with electrolytic zinc layer; may include small amounts of nickel or iron for plating.

Mechanical Properties

Both SGCC steel and SECC share the base SPCC steel properties:

• Tensile strength: moderate, suitable for forming and stamping.
• Yield strength: sufficient for typical load conditions.
• Elongation: good ductility, with SECC slightly higher due to thinner coating.
• Formability & stamping: SECC excels in precision stamping; SGCC material is robust for larger structural components.

   

Physical & Chemical Properties

• Coating hardness: SGCC harder due to thicker plating.
• Heat resistance: moderate; SGCC steel withstands higher ambient conditions.
• Weldability: Both materials allow welding, though SECC may require careful handling to prevent coating damage.
• Surface conductivity: SECC often preferred for electronics due to smoother, more uniform zinc steel sheet surface.

   

SGCC: Features, Advantages, and Applications

SGCC Features

• Thick zinc coating
• Strong corrosion protection
• Durable alloy layer
• Optional visible spangles

   

Advantages of SGCC

SGCC steel offers superior corrosion resistance, making it ideal for outdoor exposure, harsh weather, and long service life.

Disadvantages of SGCC

• Slight surface roughness
• Lower dimensional accuracy compared to SECC
• Less suitable for high-precision electronics
• More challenging to paint

   

SGCC Applications

• Construction materials
• HVAC ducts, roofing
• Outdoor structures & equipment
• Automotive frames and reinforcement parts

   

SGCC Derivatives

• SGHC, SGC340–SGC570
• Various coating weights and mechanical grades

   

Common Processing & Surface Treatments for SGCC

• Passivation
• Oiling
• Painting
• Anti-finger coating

   

SECC: Features, Advantages, and Applications

SECC Features

• Smooth, uniform surface
• Thin, precise zinc layer
• High dimensional accuracy
• Excellent paint adhesion

   

Advantages of SECC

SECC is ideal for precision stamping, electronic housings, and indoor applications requiring a flawless finish. It also provides better conductivity for electronic devices.

Disadvantages of SECC

• Weaker corrosion resistance than SGCC material
• Not ideal for outdoor use
• Higher long-term maintenance if exposed to moisture

   

SECC Applications

• Computer casings & consumer electronics
• Server racks, chassis
• Office equipment
• Small household appliances

   

Common Processing & Surface Treatments for SECC

• Powder coating
• Phosphating
• Painting
• Precision laser cutting
• Micro-bending & fine stamping

   

SGCC vs SECC: Direct Comparison

Equivalent Grades & Standards (International Comparisons)

SGCC Equivalent Grades

• JIS: SGCC → EN: DX51D+Z → ASTM: G90, Z275

SECC Equivalent Grades

• JIS: SECC → EN: DC01+ZE → ASTM: A-grade electro-galvanized

   

Standard Sizes, Thicknesses & Coating Weights

• SGCC thickness: 0.4–6.0 mm
• SECC thickness: 0.4–3.2 mm
• Zinc coating: SGCC 40–200 g/m² per side, SECC 5–30 g/m² per side
• Sheet & coil widths: vary by manufacturer

   

SECC vs SGCC: Which Should You Choose?

Choose SECC When…

• Precision stamping required

   

• Electronics/device housings

   

• Indoor applications

   

• Smooth surface needed

   

Choose SGCC When…

• Outdoor exposure
• High corrosion resistance required
• Structural integrity is priority

   

Decision Chart / Table Summary

Conclusion

SGCC steel and SECC both offer corrosion resistance and excellent workability. Choose SECC for precision indoor applications and electronics, while SGCC material is ideal for outdoor, structural, and high-moisture environments. Selecting the right material ensures durability, performance, and cost-effectiveness.

For premium-quality SGCC coil and SECC sheets, trust Delong Metal. With precise SPCC steel bases, consistent zinc coatings, and short lead times, Delong ensures durable, high-performance materials for every industrial application.