If you're considering zinc plating for your parts, one of the first questions you'll likely ask is: How long does it last? Zinc plating is widely used for its cost-effective corrosion protection, but its longevity depends on a range of factors including environment, thickness, post-treatments, and finish quality.

At The Bass Plating Company, we’ve delivered high-volume, rack-based zinc plating solutions for over 70 years. In this post, we’ll break down how long zinc plating can last, what impacts its service life, and how to get the most value out of your plated parts.

Zinc plating (also known as electrogalvanizing) is the process of applying a thin layer of zinc to metal, typically steel, to protect it from rust and corrosion. The zinc layer acts as a sacrificial coating, corroding first to protect the underlying metal.

The lifespan of zinc plating can range from a few months to over 10 years, depending on:

1. Plating Thickness: Zinc plating is measured in microns (µm) or thousandths of an inch (mils). As a rule:

• 5–8 µm (0.0002"–0.0003") = light indoor use (~6–12 months)
  
• 8–12 µm (0.0003"–0.0005") = standard industrial use (~1–3 years)
  
• >12 µm (0.0005"+) = extended outdoor protection (3–10+ years)

Bass Plating Tip: For outdoor or high-humidity environments, go thicker and add a chromate topcoat.

2. Environmental exposure: Zinc plating performs best in controlled, indoor environments. Outdoors, its life span varies. Harsh environments accelerate zinc corrosion, especially in marine or acidic atmospheres.

3. Post-treatment (e.g., chromate conversion): Adding a clear, yellow, or black chromate conversion coating dramatically increases corrosion resistance.

• Clear (trivalent): Moderate protection, RoHS compliant
• Yellow (hexavalent or trivalent): High protection, common for automotive
• Black: Aesthetic and moderate corrosion resistance

Chromates slow white rust formation and extend service life.

4. Type of substrate and usage: Post-plating treatments like sealers, topcoats, or passivation layers can improve performance. Bass Plating offers post-treatments tailored to improve corrosion resistance, enhance appearance, and meet OEM or military specs. 

In testing, zinc-plated parts are often measured by salt spray hours:

• Clear zinc: ~12–72 hours to white rust
• Yellow zinc: ~96–200+ hours
• Sealed yellow zinc: 200–500+ hours

Actual field performance depends on the application, but these benchmarks help determine plating specs.

To get the most out of your zinc plating:

• Choose the right thickness for the environment
• Use chromate conversion coatings
• Add sealers or passivation if needed
• Partner with a shop that ensures thorough surface prep and quality control

At Bass Plating, our rack plating process ensures even coverage and consistent quality, even for large or complex parts.

• High-volume capabilities
• Rack plating for uniformity
• Support for large-format parts (up to 10 ft)
• In-house chromate conversion coatings
• Over 70 years of trusted expertise

From industrial fasteners to bus bars, we plate to ASTM, MIL, and OEM specifications, on time and to spec. Wondering how long zinc plating will last for your parts? Contact our experts for a custom recommendation based on your specs and application.