Not all fire pits are created equal, and neither is the steel they are made from.
At Frontier Designs, we believe that what is underneath the surface matters. That is why we are obsessed with the material we use to build our fire pits. Steel might seem like a simple choice, but the truth is, it is one of the biggest factors that determines how your fire pit will perform, age, and endure over time.
If you are shopping for a fire pit that will last for years, or even decades, this guide will help you understand the critical differences between mild steel, cold rolled steel, and Corten steel. And why we build with only one of them.
What Is Mild Steel?
Mild steel is a generic term for low-carbon steel. It is inexpensive, easy to fabricate, and widely used across consumer-grade products, including fire pits sold at big-box stores and online marketplaces.
The problem is that mild steel is not made to last outdoors.
It is prone to rust, flaking, and corrosion when exposed to moisture and high heat. Even light weathering can eat away at the steel if it is not painted or sealed properly, and those coatings do not hold up well to the direct heat of open flame.
In short, mild steel might look good on the shelf, but it often needs replacing within a few seasons.
What Is Cold Rolled Steel?
Cold rolled steel is a type of mild steel that is processed at lower temperatures to create a smoother surface and tighter tolerances. It is stronger and more refined than standard hot rolled steel, and it is often used where appearance matters more.
But do not let the slick finish fool you.
Cold rolled steel still rusts easily and lacks the weathering properties necessary for outdoor fire pits. Once exposed to rain, humidity, or heat, it begins to break down just like mild steel. Unless it is constantly maintained and recoated, it will not last in outdoor conditions.
Cold rolled steel might be stronger than mild steel in form, but it is no match for nature.
What Is Corten Steel?
Corten steel, also known as weathering steel, is in a league of its own.
Originally developed for bridges, shipping containers, and outdoor architecture, Corten is engineered to thrive in the elements. When exposed to weather, it forms a stable, self-protecting layer of rust called a patina that actually prevents deeper corrosion.
This is not failure. It is function.
Unlike other steels that deteriorate over time, Corten steel grows stronger, more beautiful, and more resilient as it weathers. It develops a rich bronze color, resists structural decay, and requires virtually zero maintenance. It is the ideal material for outdoor fire pits that are meant to last.
Why the Patina Matters
The real difference lies in how each steel reacts to exposure. Here is how they break down:
Mild steel rusts from the inside out, weakening the structure and requiring protective coatings to survive.
Cold rolled steel may start off smooth, but it rusts quickly and unevenly unless sealed or painted, which will not last under fire.
Corten steel rusts from the outside in. Its protective layer locks in durability and eliminates the need for paint or treatment.
That evolving patina is what gives Frontier fire pits their signature look, a living surface that reflects both the strength and beauty of time.
Which One Lasts Longer Outdoors?
| Material | Corrosion Resistance | Appearance Over Time | Lifespan Outdoors | Maintenance |
|---|---|---|---|---|
| Mild Steel | Low | Rust, flaking, decay | 1 to 3 years | High |
| Cold Rolled Steel | Low | Rust, surface pitting | 2 to 4 years | Medium |
| Corten Steel | Very High | Rich bronze patina | 20 years or more | Low |
Why We Only Use Corten Steel
At Frontier Designs, we do not believe in shortcuts. That is why we craft every fire pit from thick, high-quality Corten steel, a material chosen not just for how it performs, but for how it ages.
Corten costs more to work with, but it pays off in every way that matters. It looks better, lasts longer, and requires far less maintenance over time. You will not find peeling paint, rusted legs, or pits in the surface after a few summers.
Instead, you will get a fire pit that is meant to be a permanent part of your home. A place for gathering, for reconnecting, and for creating lasting memories season after season.
The Takeaway
If you are comparing fire pits, do not just look at the shape or size. Look at the material.
Mild steel and cold rolled steel might get the job done for a while, but they are not built to last. Corten steel is. It is the only option that delivers on performance, longevity, aesthetics, and ease of ownership, which is exactly why we choose it.
When you buy a fire pit from Frontier Designs, you are not just buying a product. You are investing in something permanent, something honest, and something worth passing down.
Start with Corten.
Start with Frontier.
