galvanized strips and coils
Need S320GD galvanized steel strips and coils that meet strict surface quality requirements for visible or high-performance applications? Unlike ordinary suppliers, GNEE implements rigorous surface inspection protocols throughout production.
We provide S320GD+Z galvanized strips and coils with customized coating weights (Z60-Z275), thicknesses (0.1-6.0mm), and width ranges (600-2000mm)-all certified to meet international surface quality standards.
Galvanized Strips and Coils Package
Read on to understand the key surface quality standards for S320GD+Z galvanized strips and coils, and how we ensure consistency for your applications.
Galvanized steel strips and coils are continuous-length carbon steel products coated with zinc to resist corrosion. They're widely used in automotive parts, electrical appliances, and construction components.
S320GD galvanized steel is a high-strength, formable grade-with the "+Z" designation representing variable zinc coating weights. Surface quality directly impacts aesthetics, coating adhesion, and long-term corrosion resistance.
International Surface Quality Standards for S320GD+Z Galvanized Strip
S320GD+Z galvanized strips and coils must comply with strict international standards that define surface defects and acceptance criteria:
| Standard | Surface Quality Class | Key Requirements | Typical Applications |
|---|---|---|---|
| EN 10346 | Class A (Best) | No visible defects; uniform zinc coating; no bare spots, pits, or scratches | Automotive exterior parts, visible architectural components |
| EN 10346 | Class B (Good) | Minor, non-conspicuous defects; no impact on performance | Automotive interior parts, electrical enclosures |
| EN 10346 | Class C (Functional) | Allowable minor defects; no effect on structural performance | Structural framing, non-visible components |
| ISO 1460 | Coating Adhesion Class | Class 0: No coating detachment after bend test | All applications requiring forming |
GNEE primarily supplies S320GD+Z galvanized strips and coils of Class A and B, with Class C available for cost-sensitive structural uses.
Common Surface Defects and Acceptance Criteria for S320GD+Z
Understanding allowable defects helps ensure S320GD+Z galvanized strips and coils meet your application needs:
| Defect Type | Description | Acceptance Criteria (Class A) | Impact on Performance |
|---|---|---|---|
| Bare Spots | Uncoated steel areas | Max. 0.5mm² per m²; no more than 2 spots per coil | Increases corrosion risk if exposed |
| Pits | Small indentations in coating | Max. 1 pit per m²; diameter ≤0.3mm | Minimal impact if small and isolated |
| Scratches | Surface grooves | Max. length 5mm, depth ≤10% of coating thickness | No impact if not exposing base steel |
| Zinc Dross | Solid zinc particles on surface | No visible dross; max. 1 particle per 10m² | Can cause coating peeling during forming |
| Color Variation | Uniformity of zinc finish | Minor variation allowed; no streaking | Aesthetic issue only; no performance impact |
All S320GD+Z galvanized strips and coils undergo 100% surface inspection before shipment.
Surface Quality Testing Methods for S320GD+Z Galvanized Strip
GNEE uses advanced testing to verify surface quality of S320GD+Z galvanized strips and coils:
- Visual Inspection:
Lighting: 800-1000 lux white light
Inspection speed: Max. 10m/min for coils
Standards: Compliance with EN 10163-3
- Coating Thickness Measurement:
Method: Magnetic induction (ISO 2808)
Sampling: 5 points per meter width
Tolerance: ±10% of specified coating weight (e.g., Z275: 247.5-302.5g/m²)
- Adhesion Testing:
Procedure: 180° bend test (EN ISO 7438)
Evaluation: No coating detachment (Class 0)
- Surface Roughness Testing:
Method: Profilometer (EN ISO 4287)
Typical Range: Ra 1.5-3.0μm for S320GD+Z galvanized strips
Adhering to strict surface quality standards ensures S320GD+Z galvanized strips and coils deliver both aesthetic appeal and long-term performance.
Whether for visible automotive parts or corrosion-resistant structural components, proper surface quality directly impacts product lifespan.
At GNEE, we provide S320GD+Z galvanized strips and coils with complete surface quality certification. Contact us today to request a surface inspection report sample and a customized quotation for S320GD galvanized steel products.
- Available Steel Grade
|
Standard |
Grade |
C |
Si |
Mn |
P |
S |
Ti |
|
Forcold Forming Chinese Standard |
DX51D+Z |
0.12 |
0.50 |
0.60 |
0.100 |
0.045 |
0.30 |
|
DX52D+Z |
0.12 |
0.50 |
0.60 |
0.100 |
0.045 |
0.30 |
|
|
DX53D+Z |
0.12 |
0.50 |
0.60 |
0.100 |
0.045 |
0.30 |
|
|
DX54D+Z |
0.12 |
0.50 |
0.60 |
0.100 |
0.045 |
0.30 |
|
|
DX56D+Z |
0.12 |
0.50 |
0.60 |
0.100 |
0.045 |
0.30 |
|
|
DX57D+Z |
0.12 |
0.50 |
0.60 |
0.100 |
0.045 |
0.30 |
|
|
Forcold Forming Japanese Standard |
SGCC |
0.15 |
0.50 |
0.80 |
0.050 |
0.030 |
0.025 |
|
SGCD1 |
0.12 |
0.50 |
0.60 |
0.040 |
0.030 |
0.025 |
|
|
SGCD3 |
0.08 |
0.50 |
0.45 |
0.030 |
0.030 |
0.025 |
|
|
SGCD4 |
0.06 |
0.50 |
0.45 |
0.030 |
0.030 |
0.025 |
|
|
For Structure Japanese Standard |
SGC340 |
0.25 |
0.50 |
1.70 |
0.200 |
0.035 |
0.025 |
|
SGC400 |
0.25 |
0.50 |
1.70 |
0.200 |
0.035 |
0.150 |
|
|
SGC490 |
0.30 |
0.50 |
2.00 |
0.200 |
0.035 |
0.025 |
|
|
SGC510 |
0.30 |
0.50 |
2.50 |
0.200 |
0.035 |
0.025 |
|
|
For Structure AISI Standard |
S220GD+Z |
0.20 |
0.60 |
0.70 |
0.100 |
0.045 |
0.025 |
|
S250GD+Z |
0.20 |
0.60 |
0.70 |
0.100 |
0.045 |
0.025 |
|
|
S280GD+Z |
0.20 |
0.60 |
0.70 |
0.100 |
0.045 |
0.025 |
|
|
S320GD+Z |
0.20 |
0.60 |
0.70 |
0.100 |
0.045 |
0.025 |
|
|
S350GD+Z |
0.20 |
0.60 |
0.70 |
0.100 |
0.045 |
0.150 |
|
|
S550GD+Z |
0.20 |
0.60 |
0.70 |
0.100 |
0.045 |
0.150 |
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