Galvanized Steel Coil (GI Coil) Complete Guide 2026 | China Factory Price

📅 2026-03-19 ⏱ 2 min read 👁 4 views

As one of China’s leading galvanized steel coil manufacturers, ChinaCNU Steel New Materials provides premium GI (Galvanized Iron) steel coils and sheets to buyers across 50+ countries. This guide covers everything you need to know before purchasing galvanized steel.

What is Galvanized Steel Coil (GI Coil)?

Galvanized steel coil is carbon steel coated with a layer of zinc through hot-dip galvanizing or electro-galvanizing process. The zinc coating provides excellent corrosion protection, significantly extending the steel’s service life in outdoor and humid environments.

GI Steel Coil Specifications

Grade	DX51D, DX52D, DX53D, SGCC, S280GD, G550
Zinc Coating	Z60, Z80, Z100, Z120, Z180, Z200, Z275, Z600
Thickness	0.12 mm – 4.0 mm
Width	600 mm – 1500 mm
Surface	Regular spangle, zero spangle, big spangle, skin passed
Standard	ASTM A653, EN10327, JIS G3302, GB/T2518
Certification	SGS, BV, ISO 9001:2015

Types of Galvanized Steel Coil

Hot-Dip Galvanized (HDG) – Thicker zinc layer (Z80–Z600), best outdoor corrosion resistance
Electro Galvanized (EG) – Thin, uniform zinc layer, superior surface for painting
Zero Spangle – Smooth surface, ideal for painting and forming
Big Spangle – Decorative zinc flower, popular for roofing and fencing

Key Applications

🏗️ Construction – Roofing sheets, wall panels, purlins, steel framing
🚗 Automotive – Body panels, structural components
🏠 Home Appliances – Washing machine drums, refrigerator backs
🌾 Agriculture – Grain silos, irrigation equipment
⚡ Electrical – Cable trays, conduits, enclosures
🏭 Industrial – Storage shelves, machine housings

How to Choose the Right Zinc Coating Weight?

Z60–Z80: Indoor applications, low humidity environments
Z100–Z120: General outdoor use, moderate exposure
Z180–Z200: Roofing, moderate corrosive environments
Z275+: Coastal areas, high humidity, harsh industrial environments

Request a Free GI Steel Coil Quote

Send us your specifications — grade, zinc coating, thickness, width, quantity — and our team will reply within 24 hours with the best factory price (FOB Qingdao/Tianjin).