Galvanized
About Galvanized Steel
Galvanized steel features a protective zinc coating for excellent corrosion resistance, durability, and a spangled finish. Conforming to standards like ASTM A123, it's ideal for outdoor structures and moisture-prone environments. In-stock in Los Angeles with custom cutting available.
Quick Facts
- Material: Galvanized Steel (Zinc-Coated Carbon Steel)
- ASTM Standard: ASTM A123 (Structural), ASTM A653 (Sheet)
- Available Sizes: Tubing OD 1-3/8" to 1-7/8", Wall 14-18 ga. Sheet, flat, and pipe also available.
- Location: Los Angeles warehouse
- Services: Custom size, same-day pickup
Overview
Galvanized steel is carbon steel that has been coated with a layer of zinc to prevent corrosion. The most common method is hot-dip galvanizing, where steel parts are submerged in a bath of molten zinc. This process creates a durable, abrasion-resistant metallurgical bond between the zinc and the steel surface. The zinc acts as a sacrificial anode, protecting the underlying steel from rust even if the surface is scratched. This makes it a cost-effective choice for long-term performance in harsh environments.
The resulting finish is typically a bright, crystalline pattern known as "spangle," though it can also be matte. This protective layer significantly extends the service life of steel components, reducing maintenance and replacement costs over time. Galvanized steel is widely used for applications requiring both the strength of steel and superior resistance to atmospheric corrosion. Bobco Metals stocks a variety of galvanized products, including pipe, tubing, sheet, and flat bar, suitable for construction, fencing, agricultural, and industrial applications.
Technical Specifications
Mechanical Properties (Typical for A500 Grade B Base Metal)
| Property | Value | Unit |
|---|---|---|
| Tensile Strength | 58,000 | PSI |
| Yield Strength | 46,000 | PSI |
| Elongation | 23 | % |
Applicable Standards
- ASTM A123: Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products
- ASTM A653: Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) by the Hot-Dip Process
- ASTM A53: Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless
- ASTM A500: Standard Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing
Common Applications
- Fencing & Enclosures: Fence posts, chain-link fabric, and gates - for long-term weather resistance.
- Construction: Structural framing, roof purlins, and decking - for corrosion protection in building skeletons.
- HVAC: Ductwork, vents, and housings - to resist moisture and condensation.
- Agriculture: Livestock pens, irrigation pipes, and grain bins - to withstand outdoor exposure and animal waste.
- Automotive: Chassis components, brackets, and underbody parts - for protection against road salt and moisture.
- Outdoor Structures: Handrails, guardrails, and signposts - for public safety and low maintenance.
- Electrical Utilities: Conduit, utility poles, and tower components - for durable, long-lasting infrastructure.
- Marine: Docks, boat trailers, and hardware - for resistance to saltwater spray.
Working with Galvanized Steel
Machining
Galvanized steel machines similarly to mild steel, but the soft zinc coating can clog cutting tools. Using slower speeds, sharp tooling, and a proper coolant can help achieve a clean cut. The coating provides some lubricity during the process.
Welding
Welding galvanized steel requires special precautions. The zinc coating releases hazardous fumes when heated and must be ground away from the weld zone before starting. Proper ventilation or a respirator is critical for safety. The weld can damage the protective coating, requiring touch-up with zinc-rich paint to restore corrosion resistance.
Finishing
The galvanized finish is the primary protective layer. While it can be painted for aesthetic reasons, it requires specific surface preparation, including cleaning and the use of an appropriate primer to ensure proper adhesion to the zinc surface.
Corrosion-Resistant Material Comparison
| Material | Corrosion Resistance | Cost | Best For |
|---|---|---|---|
| Galvanized Steel | Good | Low | General outdoor, structural, fencing |
| 304 Stainless Steel | Excellent | High | Food processing, architectural, general corrosion |
| 316 Stainless Steel | Superior | Very High | Marine environments, chemical processing |
| Aluminum | Excellent | Medium | Lightweight applications, electrical, marine |
Frequently Asked Questions
Q: Can you weld galvanized steel?
A: Yes, but the zinc coating must be removed from the weld area first to prevent weld porosity and the release of hazardous zinc oxide fumes. The area must be re-protected with a zinc-rich coating after welding.
Q: How long does a galvanized coating last?
A: Service life depends on the environment. In mild, rural settings, it can last over 50 years. In harsh industrial or coastal areas, the lifespan may be reduced to 10-20 years depending on coating thickness.
Q: What is the difference between galvanized steel and stainless steel?
A: Galvanized steel is carbon steel with a protective zinc coating. Stainless steel is an alloy containing chromium, which makes the entire metal inherently corrosion-resistant, not just the surface. Stainless offers superior protection, especially against pitting and crevice corrosion.
Stock & Custom Sizes
Available round tubing ODs: 1-3/8" to 1-7/8" with wall thicknesses from 18 gauge (0.048") to 14 gauge (0.075"). Standard lengths: 24 ft. Also available in sheet, flat bar, and pipe forms. Custom size available.
Same-day cutting and Los Angeles pickup available.
View Sizes & PricingNeed Galvanized Steel? Contact Bobco Metals for availability and Los Angeles pickup.
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