Galvanized Steel Coil (GI)

Product Description

Galvanized Steel Coil (GI) is hot dip galvanized to EN 10346 or ASTM A653 standards, providing 20+ years of corrosion protection in suitable environments. The zinc coating is metallurgically bonded to the steel substrate, offering both barrier protection and sacrificial galvanic protection — meaning even if the surface is scratched, the surrounding zinc will continue to protect the exposed steel.

We supply the full range of zinc coating weights: Z80 (80 g/m² total both sides — light protection, indoor), Z120 (medium protection, sheltered outdoor), Z180 (light industrial), Z275 (heavy outdoor, the most common for roofing and HVAC), and Z350 (severe environment). Substrate grades available: DX51D+Z (commercial drawing), DX52D+Z (drawing), DX53D+Z (deep drawing), and structural grades S220GD+Z, S250GD+Z, S350GD+Z, S550GD+Z.

Spangle options affect appearance and downstream painting. Regular spangle has visible flower-pattern crystallization (traditional GI look). Minimized spangle has fine, uniform crystallization. Zero spangle has nearly invisible crystallization — preferred for visible applications and pre-painted (PPGI) substrates.

Applications of Galvanized Steel Coil (GI)

Standards Compliance for Galvanized Steel Coil (GI)

• EN 10346 — DX51D+Z, DX52D+Z, S250GD+Z, S350GD+Z (European)
• ASTM A653 — CS Type B, DDS, EDDS, SS Grade 33-80 (US)
• JIS G3302 — SGCC, SGCD, SGCD2, SGC340-SGC570 (Japanese)
• GB/T 2518 — Chinese hot dip galvanized
• AS 1397 — Australian/New Zealand galvanized
• EN 10204 type 3.1 with coating weight verification per coil

Frequently Asked Questions about Galvanized Steel Coil (GI)