Can You Put Galvanized and Stainless Steel Together?

Introduction

Mixing metals sounds like something only an engineer would care about, right? But even regular folks working on home projects, farming gear, or even DIY furniture run into this question: can you put galvanized and stainless steel together?

The short answer: Yes, but it’s tricky.

The long answer is what we’re going to explore in this blog. We’ll break it down in plain English, so you’ll know when it’s okay to mix these metals—and when it’s a bad idea. We’ll also talk about rust, reactions, and simple tips to avoid problems.

Let’s get started.

First, What Are Galvanized and Stainless Steel?

Before we get into mixing them, it helps to know what they are.

Galvanized Steel

Galvanized steel is regular steel coated with a thin layer of zinc. That zinc protects it from rusting. It’s cheap, strong, and good for outdoor use like fences, bolts, and roofing. But if that zinc coating wears off or gets scratched, the steel underneath can rust fast.

Stainless Steel

Stainless steel, on the other hand, has special ingredients like chromium that help it resist rust all the way through—not just on the surface. There are different grades, and some are shinier, stronger, or more rust-proof than others. One of the most common types is 304/18, which you’ll see in kitchen sinks, outdoor grills, and even medical tools.

If you’re working with real stainless steel, especially high-quality types like 304/18, it’s made to last—and that’s why people love it.

What Happens When You Mix the Two?

Here’s where it gets interesting.

When galvanized steel and stainless steel touch each other and there’s moisture involved (like rain, humidity, or condensation), they can start to corrode faster. This is due to something called galvanic corrosion. Don’t worry about the fancy name—here’s what it means:

It’s like a mini battery. When two different metals are connected and water gets between them, electricity starts to flow. The weaker metal (in this case, galvanized steel) starts to break down first. The zinc coating corrodes faster, and the damage can spread.

Over time, this means rust, leaks, or parts falling apart.

 

So, Can You Put Them Together?

Yes—but only if:

• There’s no water or moisture involved.
  
  
• You add a barrier or coating between the metals.
  
  
• You’re using it for short-term or light-duty jobs.
  
  

If you’re indoors and the project stays dry, like a shelving frame or indoor railing, mixing real stainless steel and galvanized steel might be fine.

But if you’re building something outdoors or in a damp space (like a basement, boat, or kitchen), it’s risky unless you take precautions.

Real-Life Example

Let’s say you’re building a garden bench. You have some c channel stainless steel left over from another project and a few galvanized bolts lying around.

If that bench sits outside and it rains often, the contact points between the bolts and the c channel stainless steel will corrode. The galvanized parts may rust and stain the stainless ones too.

Now your good-looking bench has ugly brown spots and might get weaker over time.

How to Safely Combine Galvanized and Stainless Steel

Mixing metals isn’t always avoidable, especially when you’re working with leftover parts or need a fast fix. So how do you protect your project?

1. Use a Barrier

You can place a plastic or rubber washer between the two metals. This breaks the electrical connection and keeps water from acting like a bridge.

Even painting one of the parts or adding a corrosion-resistant coating can help.

2. Keep it Dry

If you’re installing something indoors or in a covered area, you’ll lower the risk of corrosion. Still, seal the joints if possible—especially if they’re near pipes or windows.

3. Use Similar Metals

If you can, avoid mixing at all. Stick to one type of metal. If you’re using 304/18 stainless steel, try to use stainless bolts, nuts, or brackets too. It may cost a bit more up front, but it lasts way longer and saves you from future headaches.

4. Go for Hot-Dip Galvanizing

Some folks use hot-dip galvanized steel, which has a thicker zinc coating. It holds up better when touching stainless steel, but it’s still not a perfect match. Just be aware that even stronger coatings eventually wear down.

 

Where This Comes Up Most Often

You’d be surprised how often people run into this issue. Here are common situations where galvanized and stainless steel mix:

• Boat hardware: Saltwater makes corrosion worse, so never mix metals on a boat unless you use barriers.
  
  
• Outdoor decks or railings: Screws, brackets, and frames should match.
  
  
• Farm or barn equipment: Moisture, dirt, and chemicals can speed up corrosion between mixed metals.
  
  
• Furniture or art projects: Even small pieces touching each other can cause staining over time.
  
  
  
  
  
  
  
  

Does the Size of the Parts Matter?

Yes, it does!

If the stainless steel part is much larger, the corrosion of the smaller galvanized part happens even faster. That’s because the bigger piece creates a stronger reaction.

So, if you're connecting a large c channel stainless steel frame to a tiny galvanized screw—bad combo. That screw won’t last long, especially in damp areas.

Can You Just Use Stainless Steel Everything?

If you're wondering why not just switch fully to real stainless steel—you’re not alone.

Yes, it's a great option. Stainless steel lasts a long time, looks better, and doesn’t need extra coatings or protection. But here’s the catch: it’s more expensive.

That’s why many people go for galvanized steel—it’s affordable and good for a lot of everyday jobs.

 

So it really comes down to budget vs. long-term durability.

Final Tips Before You Start Your Project

• Think about where it will be used. Is it dry or wet most of the time?
  
  
• Match your fasteners. If you’re using 304/18 stainless steel, get stainless nuts and bolts too.
  
  
• If you must mix metals, use barriers. Plastic washers, paint, or tape can help.
  
  
• Check your parts often. If mixing is unavoidable, inspect them now and then for signs of rust.
  
  
  
  
  
  
  

Summary

So, can you put galvanized and stainless steel together?

Yes—but carefully.

If they touch and get wet, you’ll likely see corrosion and damage, especially to the galvanized part. To stay safe:

• Use barriers between the metals.
  
  
• Keep the project dry.
  
  
• Or better yet, stick with one type—preferably real stainless steel like 304/18 if your budget allows.