Galvalume Steel Coils (GL)

-- Steady & Reliable Manufacturer --

Introduction

Galvalume Steel Coils (GL), also known as Aluzinc, are a premium metallic-coated product. The coating is an alloy of 55% Aluminum, 43.4% Zinc, and 1.6% Silicon, applied via the hot-dip process. This unique composition offers a synergistic protection mechanism: the aluminum provides a superior barrier against corrosion, and the zinc offers sacrificial protection at cut edges. GL is widely recognized for its significantly longer service life—often 2 to 6 times that of standard galvanized steel—making it a preferred substrate for both pre-painted (PPGL) and unpainted exterior applications.

GL coils are the foundation for the most durable metal roofs and facades on the market today.

Specifications

Parameter	Value/Range
Coating Alloy	55% Al, 43.4% Zn, 1.6% Si
Coating Mass (AZ)	AZ50 to AZ200 g/m² (Most common: AZ100, AZ150)
Standard	ASTM A792, JIS G3321, EN 10346
Thickness Range	0.20mm to 1.5mm
Surface Finish	Zero Spangle, Anti-Fingerprint (Optional)
Steel Grade	Commercial (CQ), Lock Forming (LF), Structural (HSS)
Thermal Reflectivity	Excellent (up to 80%)

Performance Highlight: The Aluminum component forms an inert oxide layer, creating a highly effective physical barrier against corrosive agents.

Application

Unpainted Roofing: High-end, exposed metal roofing and siding, valued for its natural metallic sheen.
Substrate for PPGL: Used as the base for the most durable color-coated steel (Prepainted Galvalume).
HVAC/Ducting: Components requiring superior long-term weather resistance.
Agricultural Equipment: Silos and farming structures where high humidity is present.

Advantages

Extended Service Life: Far superior corrosion resistance compared to standard GI, especially in humid and marine environments.
High Heat Reflectivity: Reduces heat transfer into buildings, contributing to energy savings.
Ductility: Excellent formability for roll forming into various profiles without cracking the coating.
Attractive Finish: Provides a smooth, subtle metallic appearance when left unpainted.

Payment & Shipping

Stock Availability: Common AZ coating masses (AZ100, AZ150) and thicknesses are often stocked for quicker fulfillment.
Handling Precautions: Care is taken to prevent moisture build-up between sheets/wraps, which can lead to 'white rust' (storage stain) on metallic-coated products.
Certifications: Full testing reports validating the Al-Zn alloy ratio are provided with the Mill Test Certificate (MTC).

Frequently Asked Questions

Q: Can Galvalume be used with treated lumber (pressure treated wood)?
A: No. The chemicals in treated lumber are highly corrosive to Galvalume (and Galvanized) steel. It must be isolated using a physical barrier like flashing or foam tape.

Q: Is the Al-Zn coating toxic for rainwater harvesting?
A: Galvalume is generally safe for non-potable rainwater collection after the initial curing period. For potable (drinking) water, specific local regulations and certified coatings must be consulted.

CONTACT WITH US

Zhejiang Tiannv Color Steel Co., Ltd.

Enjoying good reputation from all the customers worldwide, we are the reliable partner you can trust in China.

Zhejiang Tiannv Color Steel Co., Ltd was established in January 2003, located in Zhejiang Province, which is a Sino-Hong Kong joint venture with a registered capital of 50 million RMB. As China Galvalume Steel Coils (GL) Manufacturers and Galvalume Steel Coils (GL) Factory, the company covers an area of 50000㎡, and a workshop area of 12000㎡. Company’s main products are hot galvanized steel coil, aluzinc coil, prepainted steel coils (PPGI / PPGL), prepainted aluminum coil, printed PPGI for household appliance, roofing/corrugated PPGI sheet, and PPGI paint. Currently, we have 85 skilled employees, 5 professional engineers and 15 experienced office personnel. The manufacture capability of our production line is nearly 100,000 metric tons per year.

Our company produces high quality color coated steel, and imposes strict quality control over the prepainted steel coils. We use good quality hot-dip galvanized steel coils or Alu-Zinc coated steel coils as base sheet and strictly select coated paints, which gives quality promise to customers and competitive advantage for our company.