When it comes to choosing the right steel for your project, corrosion resistance is often at the top of the priority list—especially in industries like construction, automotive, HVAC, and agriculture. That’s where galvanized steel shines. But not all galvanized steel is created equal.
The most common types—G30, G60, G90, and G235—offer different levels of zinc coating, which directly affects durability, performance, and cost.
So, what’s the difference between these galvanized steel types? And how do you know which one is right for your application? Let’s break it down.
What Is Galvanized Steel?
Galvanized steel is carbon steel coated with a layer of zinc to protect it from rust and corrosion. The zinc acts as a sacrificial barrier, slowing oxidation by preventing moisture and oxygen from reaching the steel underneath.
The “G” designation refers to the zinc coating weight, measured in ounces per square foot (oz/ft²) for both sides of the sheet. Higher numbers mean thicker coatings and better corrosion protection.
Zinc Coating Comparison Table
Type | Zinc Coating (oz/ft²) | Approx. Thickness (microns) | Corrosion Resistance | Common Uses |
G30 | 0.30 total (0.15 per side) | ~2.5 µm per side | Light protection | Indoor framing, appliance parts |
G60 | 0.60 total (0.30 per side) | ~5 µm per side | Moderate protection | HVAC systems, light-duty outdoor framing |
G90 | 0.90 total (0.45 per side) | ~7.5 µm per side | High protection | Roofing, siding, agricultural equipment |
G235 | 2.35 total (1.175 per side) | ~20 µm per side | Maximum protection | Guardrails, pole barns, marine/coastal structures |
Choosing the Right Coating for Your Project
- G30: The most cost-effective for indoor or dry environments. Common in appliance components or interior studs.
- G60: A balanced choice for moderate exposure—ideal for framing, ductwork, or areas with occasional humidity.
- G90: A trusted standard for outdoor durability, offering solid performance in roofing, farm structures, and coastal regions.
- G235: The thickest standard zinc coating available. Ideal for high-corrosion environments like marine, agriculture, and highway infrastructure (e.g., guardrails).
While heavier coatings offer better protection, they also increase cost and may be less suitable for deep forming or spot welding. Always balance coating weight with your application needs.
Hascall Steel: Your Galvanized Steel Source
At Hascall Steel, we stock a wide range of galvanized steel coil and sheet—including G30, G60, G90, and G235coatings. Whether you need light-duty interior panels or rugged outdoor components, our inventory has you covered.
Why Choose Hascall Steel?
- Inventory Variety – G30 to G235 in multiple thicknesses and widths
- Custom Processing – Slitting, shearing, and blanking in-house
- Fast Turnaround – Strategically located facilities to meet your timeline
- Expert Support – Helping you match material to your specs and budget
Need Galvanized Steel You Can Trust?
Let’s talk. Contact us today to:
- Get pricing and availability
- Confirm the right coating for your environment
- Request samples or spec sheets