Zinc Plated vs Stainless Steel Anchors
Asphalt Anchors are available in zinc plated carbon steel and 304 stainless steel. Both versions have the same published strength ratings. Choose between them based on corrosion exposure, expected service life, and project budget.
Short answer
Section titled “Short answer”Use zinc plated anchors for most installations with normal outdoor exposure. Use stainless steel anchors when corrosion exposure is high or long-term service life is more important than the lowest upfront cost.
Which material should I choose?
Section titled “Which material should I choose?”| Application or environment | Recommended material | Why |
|---|---|---|
| Residential driveway, inland location | Zinc plated | Good corrosion protection at the lowest cost. |
| General parking lot equipment | Zinc plated | Suitable for typical outdoor exposure when salt and chemicals are limited. |
| National rollouts where cost matters | Zinc plated | Large customers have selected zinc after year-plus evaluations for nationwide deployment. |
| Snow belt roads and parking lots | Stainless steel | Better choice where anchors are exposed to road salt and winter weather. |
| Transportation infrastructure | Stainless steel | Common choice for high-exposure installations with salt, weather, and heavy use. |
| Direct coastal exposure | Stainless steel | Better resistance to corrosion from salt air and moisture. |
| Chemical, washdown, fertilizer, or oil exposure | Stainless steel | Better long-term choice when corrosive chemicals may reach the anchor or bolt threads. |
Zinc plated carbon steel
Section titled “Zinc plated carbon steel”Our zinc plated anchors are carbon steel anchors with a zinc protective coating. The zinc layer protects the steel from normal outdoor moisture and weather exposure, and it is the best value for most projects.
We have had zinc plated anchors installed for more than 10 years in West Orange, New Jersey. In 2025, we removed anchors from that installation specifically to inspect them for rust. We observed minimal surface rusting on the anchors.
Zinc plated anchors are also commonly chosen by larger customers after extended evaluations. Some large customers have run year-plus evaluations for nationwide deployments and selected zinc plated anchors for the rollout.
Zinc plating is still a coating. If the anchor is exposed to road salt, direct coastal air, standing water, or corrosive chemicals, stainless steel is usually the better long-term choice.
304 stainless steel
Section titled “304 stainless steel”Our stainless anchors are 304 stainless steel. Stainless steel provides corrosion resistance through the material itself rather than only through a surface coating.
Choose stainless steel for installations exposed to road salt, direct coastal weather, high moisture, or corrosive chemicals. Transportation customers often choose stainless steel because anchors may see both weather and road salt over long periods.
Stainless steel costs more than zinc plated carbon steel, but it is the right choice when corrosion exposure is high or future maintenance access is limited.
Strength is the same
Section titled “Strength is the same”Zinc plated and stainless steel anchors have the same published strength ratings. Choose the material for corrosion resistance, not for holding strength.
Anchor holding strength is driven primarily by anchor size, asphalt condition, adhesive selection, hole preparation, embedment, and operating temperature. For strength data, see Anchor Strength Testing and the Installation Guide.
Bolts, washers, and anti-seize
Section titled “Bolts, washers, and anti-seize”The anchor is only one part of the fastening system. For corrosion-prone installations, use bolts and washers with corrosion resistance appropriate for the environment.
When supplying your own bolts, protect the threads with anti-seize lubricant so the bolts can be removed in the future:
- Use Permatex #80078 for zinc plated or steel anchors.
- Use Permatex #77124 for stainless steel anchors.
Anti-seize is especially important with stainless steel hardware because stainless threads can gall if assembled dry.
When to ask us
Section titled “When to ask us”Contact us if your project involves direct coastal exposure, heavy road salt, chemicalsm, or public infrastructure. We can help you choose the right material for the environment.