Galvanized Coil (GI Z275)

Description

1. Product Overview
The Galvanized Coil (GI Z275) is a high-performance, hot-dip zinc-coated steel product featuring a symmetrical Z275 coating mass (275 g/m²) on both sides, delivering superior corrosion resistance for demanding structural and manufacturing environments. Primarily used in construction, automotive components, and heavy industrial equipment, this coil serves as the backbone for roll-forming, stamping, and cold-rolling operations. Its strategic value lies in balancing extended service life with formability—offering a lower total cost of ownership compared to standard galvanized alternatives—making it the preferred substrate for mission-critical, long-life applications.

2. Key Specifications & Technical Characteristics

• Base Metal: Commercial steel (DQ – Drawing Quality optional), thickness range 0.25 mm – 3.0 mm, width 600 mm – 1,500 mm

• Coating Mass: Z275 (275 g/m² total both sides, ~19–21 µm per side per ASTM A653 / EN 10346)

• Coating Type: Hot-dip galvanized, spangle (regular, minimized, or zero spangle available)

• Surface Finish: Chemically passivated (Cr-free optional), oiled or dry, with anti-fingerprint treatment available

• Mechanical Strength: Yield strength 220–350 MPa (Grade DX51D+Z to S350GD+Z)

• Coil ID: 508 mm or 610 mm; maximum OD: 2,000 mm

• Coil Weight: 5–15 MT per coil (standardized)

• Packaging: Eye-to-side or eye-to-sky, with VCI paper, moisture-proof wrap, galvanized strapping, and plywood skid for export

• Shelf Life: 12 months (indoor, dry, ≤60% RH) without white rust formation under proper storage

3. Core Industrial Applications

• Construction (roofing, wall cladding, purlins): Z275 outperforms lighter coatings (Z100–Z180) by 2–3× in salt-fog resistance (ASTM B117 >720 hrs), reducing maintenance cycles in humid or coastal environments.

• Automotive & Trucking (floor panels, structural brackets, underbody shields): Superior adhesion for welding and painting compared to Z350 (brittle) or Z180 (low life), enabling deep drawing without micro-cracking.

• HVAC & Electrical enclosures (ducting, cabinets, switchgear): The uniform zinc layer eliminates edge creep corrosion better than batch galvanizing, while the smooth surface reduces secondary finishing costs.

• Agricultural equipment (grain bins, silos, feeders): Acid-resistant passivation (optional) extends life in ammonia/organic acid atmospheres—an advantage over non-passivated coils.

4. Competitive Advantages

• Quality consistency: ISO 9001:2025-certified mills with in-line coating weight controls (XRF verified); statistical tolerance ±5% vs. industry average ±10%.

• Supply reliability: Dual-sourced from Tier-1 Korean and Vietnamese mills; 98% on-time delivery track record with 3-week lead times (vs. 6–8 weeks industry).

• Logistics capability: Containerized or break-bulk; standard 20’ GP loads 22–25 MT, with fumigated crating for mold/moisture protection during sea freight.

• Price competitiveness: Direct mill allocation eliminates 2–3 intermediary margins; locked-in quarterly pricing available for 500+ MT contracts.

• Sustainability: Lead-free coating; 100% recyclable steel substrate with ≤12% recycled pre-consumer zinc scrap; compliant with RoHS, REACH, and LEED v4 material credits.

• Technical support: Full material test certificates (EN 10204 3.1), welding/painting guidelines, and FEA-grade mechanical property data sheets provided with every shipment.

5. Commercial & Supply Information

• Minimum Order Quantity (MOQ): Bulk 20 metric tons (MT) per size/gauge combo

• Loading capacity (20’ container): 22–25 MT (depending on coil OD and strapping method)

• Loading capacity (40’ container): 48–50 MT (edge-protected double-stacking permitted)

• Incoterms: FOB, CIF, CFR, EXW (mill door)

• Lead time: 14–21 days from LC or 30% deposit confirmation

• Documentation: Commercial invoice, packing list, BL, certificate of origin, mill test certificate, fumigation certificate, insurance (optional)