Galvanized Steel Strip (short for GI Strip) is narrow steel coil made from cold rolled or hot rolled low-carbon steel substrate, processed by continuous hot-dip galvanizing to form a metallic zinc coating on the surface. The zinc layer greatly improves corrosion resistance, and it serves as the core raw material for pre-galvanized welded pipes and cold-formed profiles.
Glory Steel is a professional manufacturer & exporter of HDG steel strips. Our products feature uniform zinc coating and strict dimensional tolerance after slitting. Custom zinc coating, thickness and slitting width are available, complying with global standards.
Specifications
| Item | Galvanized Steel Strip / GI Strip |
|---|---|
| Material Grade | Q195, Q235B, Q355B; DX51D+Z, DX52D+Z, EN S235JR / S355JR, ASTM A653 |
| Process | Hot-dip galvanizing |
| Thickness | 0.12mm – 4.0mm |
| Width | 7mm – 1250mm (custom slitting available) |
| Zinc Coating Weight | 30g/㎡ ~ 275g/㎡ (Z30~Z275), total weight on both sides |
| Zinc Spangle | Zero spangle, minimum spangle, regular spangle |
| Surface Treatment | Chromate passivation (C), oiled (O), lacquer sealed (L), phosphated (P), untreated (U) |
| Coil Inner Diameter | 508mm / 610mm |
| Coil Weight | 1–5 tons per coil |
| Product Form | Steel coil, cut-to-length flat strip, slit narrow strip |
| MOQ | 10 Tons |
Note: Common zinc coating grades for hot-dip galvanized steel strip: Z80, Z120, Z150, Z275.
Product Classification
1. By Galvanizing Process
- Hot-dip Galvanized Steel Strip: Thick zinc coating (30–275g/㎡), superior anti-corrosion performance. The zinc-iron alloy layer bonds firmly, suitable for long-term outdoor and humid environments.
- Electro-galvanized Steel Strip: Thin zinc coating (10–30g/㎡), excellent surface quality and formability, ideal for home appliances and electronic housings requiring high appearance and painting performance.
2. By Surface Structure
- Regular Spangle: Traditional hot-dip galvanized surface with obvious zinc spangles and good corrosion resistance.
- Minimum Spangle / Zero Spangle: Uniform and smooth surface, suitable for painting and applications with high appearance requirements.
3. By Substrate & Application
| Substrate Type | Common Grades | Features |
|---|---|---|
| Cold Rolled Substrate | DX51D+Z, DX52D+Z, DX53D+Z, SGCC, SPCC | Fine surface quality and good formability |
| Hot Rolled Substrate | Q195, Q235, SS400 | High strength and lower cost |
Cold rolled galvanized substrate graded by forming performance: DX51D+Z (commercial grade), DX52D+Z (drawing grade), DX53D+Z (deep drawing grade). SPCC is cold rolled black substrate for subsequent galvanizing.
Product Advantages
- Long-lasting Corrosion Resistance: Uniform and dense zinc layer metallurgically bonded to the substrate, hard to peel off. It resists moisture, salt spray and industrial atmospheric corrosion. Thicker zinc coating brings better stability under harsh conditions.
- Strong Process Adaptability: Excellent performance for cold bending, punching, spot welding / seam welding, ready for processing into pipes and various profiles.
- High Dimensional Accuracy: Well-controlled edge burrs after slitting and flat strip shape, perfectly matching automatic ERW pipe production lines and precision stamping.
- Good Paint Adhesion: Passivated or phosphated surface delivers excellent paint adhesion, making it premium substrate for prepainted steel coil.
- Export-Friendly: Passivation and oiling treatments can be applied to prevent white rust during sea shipment, meeting procurement standards for climates worldwide.
Mechanical Property Reference
| Grade | Yield Strength Rp0.2 (MPa) | Tensile Strength Rm (MPa) | Elongation A (%) | Application Grade |
|---|---|---|---|---|
| DX51D+Z | — | 270–500 | ≥22 | Commercial / Bending |
| DX52D+Z | 140–300 | 270–420 | ≥26 | Drawing |
| DX53D+Z | 120–220 | 260–350 | ≥36 | Deep Drawing |
| Q195 | ≥195 | 315–430 | ≥33 | General Structure |
| Q235 | ≥235 | 370–500 | ≥26 | Structural Parts |
Main Applications
- Pipe Manufacturing: Pre-galvanized ERW round pipe, square & rectangular pipe, elliptical pipe, greenhouse pipe, low-pressure fluid transmission pipe.
- Steel Construction: Light steel keel, C/Z purlin, roof support, roller shutter door, cable tray, prefabricated house.
- Home Appliance & Hardware: Internal & external components for washing machines, refrigerators and air conditioners, electrical cabinets, storage racks, filing cabinets.
- Fencing & Agriculture: Chain link fence posts, fence clamps & end caps, greenhouse accessories, livestock troughs and manure channels.
- Packaging & Automotive: Steel strapping, binding strips for pipe ends; light automobile internal structural parts and auxiliary chassis components.
Typical Sizes
| Thickness (mm) | Width (mm) | Zinc Coating (Both Sides) | Surface Treatment | Application |
|---|---|---|---|---|
| 0.5 | 1000/1250 | Z60–Z275 | Zero spangle / Passivated | Home appliance parts, steel keel |
| 0.8 | 1000/1250 | Z60–Z275 | Regular spangle | Purlin, ventilation pipe |
| 1.0 | 1000/1250 | Z80–Z275 | Zero spangle / Oiled | Automotive inner panels, racks |
| 1.5 | 1250 | Z120–Z275 | Regular spangle | Agricultural facilities |
| 2.0 | 1250 | Z120–Z275 | Regular spangle | Heavy-load structures |
Production Process
Hot-dip galvanizing workflow: Cold/hot rolled steel strip → Uncoiling → Welding → Degreasing & Cleaning → Annealing & Reduction → Hot-dip galvanizing → Air knife zinc thickness control → Cooling → Passivation / Phosphating / Oiling → Recoiling → Dimension inspection → Packing & shipment.
Key process explanation:
Annealing & reduction removes internal stress and activates steel surface to guarantee zinc adhesion. Air knife precisely controls zinc coating thickness for uniform coating on both sides. Post-treatment (passivation / oiling) prevents white rust during ocean transportation.
Market Price Reference
Note: Prices fluctuate with zinc ingot price, specifications, and exchange rate. Below are recent FOB reference prices from major Chinese ports:
- Regular commercial hot-dip galvanized strip (zinc 40-60g/㎡, thickness 0.3-1.0mm): USD 580 – 650 / MT.
- Heavy zinc coating anti-corrosion hot-dip galvanized strip (zinc 120-275g/㎡): USD 680 – 780 / MT.
- Electro-galvanized steel strip (zinc 10-30g/㎡): USD 620 – 700 / MT.
- Narrow strapping strip (width 9.5- 50 mm): USD 600 – 680 / MT.
- Special surface treatment (zero spangle/passivation / oiling): + USD 20 – 50 / MT on base price.
Regional Market Overview
Different overseas markets have different preferences for galvanized steel strip:
- Southeast Asia, Central Asia, Middle East: Hot-dip galvanized strip for construction, commonly 0.3–1.0mm thickness, regular spangle with oiled / passivated finish.
- Europe, Australia: High requirements on surface quality & environmental standards, zero/minimum spangle passivated strip preferred for home appliances and light structural components.
- Africa, South America: Cost-effective general building materials and narrow strapping orders.
Why Choose Us
- Direct from Factory: Own production lines, no middleman markup, competitive price for long-term supply.
- Wide Range In Stock: Ready inventory of various thickness, width, zinc coating and grades for fast delivery.
- One-stop Steel Strip Solution: Besides galvanized strip, we also supply cold rolled strip, prepainted steel strip, together with slitting and cut-to-length processing service.
- Free Sample Service: Samples available upon request to help you confirm specifications.
FAQ
Q: What does Z275 mean?
A: Z275 means total zinc coating weight on both sides minimum 275g/㎡, approx. 137.5g/㎡ per side. Higher number means better corrosion resistance.
Q: Which regions do you export to?
A: We mainly export to Southeast Asia, Middle East, Africa, South America, Europe and Australia. Familiar with local customs clearance and standards. We do not serve the US market for the time being.
Q: Can you provide test certificates?
A: Yes. We can supply material test certificate, zinc coating test report and mechanical property report, and support third-party inspection.
Glory Steel Plant, located in Tianjin, China, is an ISO 9001, ISO 14001, and CE‑certified factory with an annual output of 100,000 tons. We specialize in the production of hot-dip galvanized steel strips and galvanized steel coils, and offer custom slitting and zinc coating options, as well as OEM/ODM services. With stable quality and comprehensive service, we export to over 120 countries.
