SECC

SECC is a Japanese Industrial Standard (JIS) designation for electrolytically galvanized steel sheets (electrolytically zinc-coated cold-rolled steel sheets). Its full name is "Steel, Electrolytically Zinc-Coated, Cold-Rolled." It is a cold-rolled steel sheet treated with electrolytic zinc plating. It is widely used in electronics, home appliances, and precision manufacturing.
I. SECC Core Characteristics
Production Process
SECC uses cold-rolled low-carbon steel sheets (usually SPCC grade, corresponding to ordinary cold-rolled steel sheets) as the substrate. A uniform zinc coating is deposited on the surface through an electrolytic galvanizing process. Compared to hot-dip galvanizing (such as SGCC), electrolytic galvanizing produces a thinner coating (typically 5-20g/m²), more uniform coating, and a smoother surface finish, making it suitable for applications requiring high aesthetics and precision. Performance Characteristics
Corrosion Resistance: Better than ungalvanized cold-rolled steel, but slightly less corrosion-resistant than hot-dip galvanized steel (such as SGCC) due to the thin coating. Suitable for dry indoor environments or applications requiring subsequent painting.
Workability: The cold-rolled low-carbon steel base provides excellent stamping and bending properties, meeting the molding requirements of precision components.
Conductivity: The zinc coating offers excellent conductivity, making it suitable for electronic device housings, brackets, and other applications.
II. SECC Sub-Types
Based on surface treatment and application, SECC has the following common sub-grades (according to JIS standards):
SECC (Original): Basic model with no additional surface treatment, suitable for applications requiring subsequent painting or electroplating.
SECC-N5: Chromate-passivated (fingerprint-resistant) surface treatment offers a certain degree of corrosion resistance and anti-fingerprint properties. Commonly used in home appliance panels and electronic housings (such as computer cases and printer cases).
SECC-P: Zinc phosphate-coated surface treatment improves paint adhesion, making it suitable as a coating substrate. III. Applications
SECC, due to its smooth surface, high precision, and excellent machinability, is primarily used in:
Electronic equipment: mobile phone/computer housings, motherboard brackets, connectors, transformer housings.
Household appliance components: microwave oven linings, air conditioner panels, washing machine control boxes.
Precision machinery: small stamped parts, instrument housings.
IV. Differences from Similar Grades
Grade Process Coating Thickness Corrosion Resistance Typical Applications
SECC Electrolytically galvanized Thinner (5-20 g/m²) Medium Electronics and precision components
SGCC Hot-dip galvanized Thicker (30-100 g/m²) High Outdoor structures, automotive chassis
SPCC Ungalvanized None Poor Basic components requiring subsequent painting
Summary
SECC is a representative example of electrolytically galvanized cold-rolled steel sheet. Its core advantages are "high precision, good surface finish, and easy machinability," making it irreplaceable in applications requiring high aesthetics and precision. When choosing, you need to pay attention to its corrosion resistance limitations (not suitable for outdoor or high humidity environments). If necessary, you can match it with painting or choose a model with thicker coating.