Picking the correct material for your project is a necessity. The wrong option can cost too much, be too difficult to manufacture, and might break when installed. The good news is that our experts at Rapid Axis have experience working with a wide range of materials. We know which options are a good choice, based on the specifics of your project.
Our experts put together this quick guide to explain the differences between galvanized steel and aluminum, and help you better understand which choice is better for your next project.
What Is Aluminum?
Aluminum is a light-weight, non-magnetic metal that is incredibly common. It’s hard to go a day in a machine shop without doing a project with aluminum, and it can be found in almost every industry from consumer products to military and aerospace applications.
Aluminum has an impressive strength-to-weight ratio, while still being very affordable and readily-available. It can be bent, welded, machined, turned, and assembled with no problems at all.
Pure aluminum is basically useless; it’s so soft that it can be damaged and deformed with very little effort.
For that reason, it’s hard to find pure aluminum, especially in a machine shop. Instead, we (almost) exclusively use aluminum alloys, which are a combination of aluminum with other elements and materials that change the mechanical properties of aluminum.
The most common alloy is 6061, which adds magnesium, silicon, chromium, iron, zinc, manganese, and copper to make the aluminum stronger, more durable, corrosion-resistant, and longer-lasting.
Through the right combination of elements, you can find aluminum that is thermally and electrically conductive, lighter-weight, stronger, more corrosion resistant, has higher fatigue resistance, and has better formability.
Pros and Cons of Aluminum
The biggest benefit of aluminum is arguably the fact that it is so affordable, easy to work with, and has a great strength-to-weight ratio. These three reasons alone are why so many people use aluminum as their go-to metal for manufacturing projects.
With the right alloy, you can improve these properties and make aluminum parts that work perfectly in your application. This is why you’ll find aluminum used in so many major industries like aerospace, defense, robotics, electronics, and much more.
Plus, aluminum alloys are corrosion-resistant without any finishing steps, and they can be further enhanced with an anodization.
The downside is that aluminum has a worse strength-to-weight ratio than titanium and a lower overall strength value than steel, making it an “in-between” type of metal. If you need a metal to handle heavy loads, then aluminum is going to fail before steel and might not work in the first place.
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What Is Galvanized Steel?
Galvanized steel is carbon steel that has gone through the galvanization process, which entails adding a thick layer of zinc to make the part corrosion-resistant. With galvanized steel, the zinc acts as a sacrificial layer that corrodes and gets damaged before the steel does.
Since galvanized steel is so durable and strong, it is often used in construction projects and in industrial equipment. It has great corrosion-resistance and tensile strength, but it’s a lot heavier than aluminum.
Galvanized steel comes in different thicknesses and can be welded, formed, and punched with the right settings. Machining galvanized steel is harder because going through the zinc layer creates fumes that damage tooling. In most cases, we machine the part before galvanizing it.
Pros and Cons of Galvanized Steel
Galvanized steel is used for its strength and durability, especially in applications that involve heavy loads or outdoor exposure. The zinc coating lasts a long time, and it can be reapplied if it gets too damaged in the future.
Additionally, galvanized steel is more affordable than stainless steel while offering similar corrosion resistance. This strikes a nice balance between strength, cost, and performance.
However, galvanized steel is really hard to machine and alter once the coating is applied. It requires special tools to prevent damage or contamination. Adding the coating also introduces a non-uniform thickness to parts, which makes it hard to use them in tightly-toleranced projects. To hit dimensional tolerances, we might need to do a post-processing step after fabrication.
Another issue is that steel is about three times heavier than aluminum. This makes galvanized steel a poor choice for parts that need to be lifted by hand or supported by other components that aren’t as strong.
Aluminum vs Galvanized Steel
Picking between aluminum and galvanized steel is one of the easier choices since these two materials are pretty different, with unique specialties and drawbacks.
If your next project requires faster turnarounds and has a lower budget, then aluminum is a great choice. It’s easier and faster to machine, and the project costs tend to be less expensive. Aluminum is also the better option if you need to keep your part lightweight or it doesn’t need to handle heavy weights.
Galvanized steel is the perfect option for high-strength parts that need to support a lot of weight without corroding. When it comes to structural parts or industrial assemblies, galvanized steel is happy to do the heavy lifting, while aluminum is typically better for trim or ornamental pieces within the same industrial equipment.
In aerospace projects, it’s more rare to see galvanized steel used since lightweight parts are preferred.
| Aluminum | Galvanized Steel | |
| Weight | Lightweight and easy to handle | Heavy; roughly 3× heavier than aluminum |
| Strength | Moderate strength; lower load-bearing capacity | High strength; excellent for structural and load-bearing parts |
| Machinability | Very easy to machine, bend, weld, and fabricate | Difficult to machine after galvanizing; often processed before coating |
| Cost | Generally affordable with low machining costs | More affordable than stainless steel, but more expensive than aluminum |
| Best Use Cases | Lightweight parts, aerospace, robotics, electronics | Structural components, construction, outdoor and industrial equipment |
Conclusion
Overall, galvanized steel and aluminum are both strong, corrosion-resistant metals that can last a really long time. With more strength available, galvanized steel is the better choice for handling heavy masses, while aluminum’s lightweight nature is good for keeping things light.
If you’re still not sure, reach out to our team at Rapid Axis. We can look at your design and project specifications to suggest which material is best for your parts.
With extensive experience with both aluminum and galvanized steel, plus dozens of other materials, you can trust Rapid Axis for all of your prototyping or production manufacturing needs. We have the equipment, expertise, and finishing options necessary to make sure all of your parts work perfectly within your unique applications.
Get a quote today, and see how Rapid Axis can help you.
