G450 Steel Grade
High-Tensile Galvanized Steel for Structural and Cold-Formed Applications
G450 Steel Technical Specifications & Applications
G450 steel is a continuous hot-dip galvanized structural steel conforming to the Australian Standard AS 1397. It features a minimum yield strength of 450 MPa and is coated with a uniform hot-dip galvanized layer that significantly enhances corrosion resistance and service life. Thanks to its high strength and excellent formability, G450 steel is widely used in construction, machinery manufacturing, and light steel structures.
As a flagship product of Hengze Steel Group, G450 steel delivers consistent quality and strict compliance with standards, meeting the high-performance demands of galvanized structural steel customers worldwide.
Table of Contents
1. Typical Uses & Selection Guidance
Structural cold-formed members (purlins, channels): G450 provides the higher yield strength needed for lighter, stiffer sections.
Coated building parts subject to weather: The hot-dip zinc coating adds corrosion protection for long service life in many environments.
Fabrication tips: Because the yield/tensile ratio is high, allowance for springback and forming limits should be accounted for in tooling and bending radii. Perform sample forming trials for complex shapes.
2. Technical Specifications Table
1. Chemical Composition Requirements (Max %)
| Steel Grade | Carbon (C) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) |
|---|---|---|---|---|
| G450 | 0.20 | 1.20 | 0.04 | 0.03 |
2. Mechanical Property Requirements
| Steel Grade | Min. Yield Strength (MPa) | Min. Tensile Strength (MPa) | Min. Elongation (%) Lo=50mm | Min. Elongation (%) Lo=80mm | Bend Angle (°) | Mandrel Diameter (× thickness t) |
|---|---|---|---|---|---|---|
| G450 | 450 | 480 | 10 | 9 | 90 | 4t |
3. Coating Adhesion Requirements (180° Bend Test)
| Coating Class | Mandrel Diameter (× thickness t) |
|---|---|
| Z, ZA, ZF, ZM (Z100, ZA90, ZF80, ZF100) | 0t |
| Z200, ZA135, ZA180, ZM90, ZM120, ZM150, ZM180 | 2t |
| Z275, ZA225, ZA275, ZM220, ZM275 | 2t |
| Z350, ZA350, ZM350 | 2t |
| Z450, ZA450, ZM450 | 3t |
| Z600 | 2t |
| AZ150, AM100, AM125, AM150 | 2t |
| AZ200, AM175, AM200, AM225 | 2t |
4. Hot-Dip Metallic Coating Types Applicable for G450 Steel
| Coating Type Abbreviation | Description |
|---|---|
| Z | Zinc coating |
| ZA | Zinc-Aluminium alloy coating |
| ZF | Zinc-Iron alloy coating |
| ZM | Zinc-Magnesium alloy coating |
| AZ | Aluminium-Zinc alloy coating |
| AM | Aluminium-Magnesium alloy coating |
3. G450 vs G450S — what’s the difference?
G450: Standard cold-rolled, metallic-coated product with nominal mechanical properties.
G450S: Skin-passed variant — the strip receives a light skin pass to improve flatness, surface appearance and paintability; commonly specified for thinner gauges and architectural visible panels.
G450 Steel FAQ：
A: Minimum yield strength is 450 MPa.
A: G450 is typically supplied as hot-dip galvanized (zinc-coated) sheet/coil; coating type and mass depend on the supplier and product spec.
A: Yes — it is commonly used for purlins, rails and other cold-formed structural sections, but forming trials and proper bend radii should be validated.
A: They represent similar high-strength coated structural steel classes in different regional standards. Always compare specific mechanical and coating requirements in each standard and check mill certificates to confirm equivalence.
About Hengze Steel Group
After galvanizing:
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Rapid Cooling: Using water quenching or air blast coolers to fix the zinc layer.
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Passivation: Chromate or non-chromate solutions are applied to improve corrosion resistance and storage life.
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Oiling (Optional): Light oil film application prevents white rust during transport and storage.
Advanced coil lines use electrostatic oilers and drying tunnels to ensure even application without compromising downstream processability.
