Behind the Scene: Materials That Make Fire Pits Last
When you invest in an outdoor fire pit, you’re not just buying a source of warmth—you’re creating a centerpiece for your backyard, a place where stories are shared, and memories are made. That’s why material matters.
At Puget Sound Fire Pits, our handcrafted RB73 fireplaces are made from 3 mm COR-TEN steel, a choice rooted in both science and aesthetics. More than just a metal, COR-TEN is the key to longevity, beauty, and performance in the damp, ever-changing Pacific Northwest climate.
But why does it matter? Let’s go behind the scenes and explore the material science and benefits that make these fire pits last for decades.
The Science of COR-TEN Steel
Origins in Innovation
COR-TEN steel (short for CORrosion resistance + TENsile strength) was first developed by U.S. Steel in the 1930s. Originally created for industrial use—think railcars, shipping containers, and bridges—it was engineered to handle exposure to the elements without breaking down.
What set it apart was its unique composition. Unlike ordinary carbon steel, COR-TEN includes copper, chromium, nickel, and silicon, giving it enhanced weather resistance and structural strength.
How It Works
Most metals rust in a destructive way—moisture and oxygen corrode the surface, flaking it away until the steel weakens and fails. COR-TEN, on the other hand, turns rust into a feature.
Here’s what happens:
Initial Oxidation: When exposed to the elements, COR-TEN begins to rust like any other steel.
Patina Formation: Instead of continuing to degrade, the rust stabilizes into a dense, protective layer called a patina.
Barrier Effect: This patina adheres to the steel, shielding the inner layers from further corrosion.
This process usually takes 2 to 6 months, depending on the weather, and results in a striking reddish-brown finish.
10x More Durable Than Standard Steel
Because of its protective patina, COR-TEN steel can last up to 10 times longer than ordinary steel in outdoor conditions. It offers comparable strength to stainless steel but with a warmer, more natural aesthetic.
Why COR-TEN Steel Matters for Fire Pits
When you’re designing an outdoor fireplace, the choice of material makes all the difference in durability, maintenance, and appearance.
Built for the Pacific Northwest
The PNW’s climate is notoriously challenging for outdoor materials. Rain, humidity, salt air, and frequent wet-dry cycles cause rapid deterioration in most metals.
COR-TEN thrives here. In fact, those alternating wet and dry periods are exactly what help its patina develop and stabilize. While ordinary steel rusts away, COR-TEN only grows stronger and more beautiful.
No Need for Paint or Sealants
Unlike other metals, COR-TEN doesn’t need to be painted, powder-coated, or sealed to survive outdoors. That means:
No peeling or flaking finishes.
No costly repainting or refinishing.
Less maintenance overall.
Nature does the finishing for you.
A Living Piece of Art
COR-TEN isn’t just durable—it’s also aesthetic. The patina matures over time, shifting from bright orange to deep, earthy tones. This evolution turns every fire pit into a unique, living sculpture that tells the story of your space.
Whether your style is rustic, modern, or eclectic, the rich tones of COR-TEN complement wood, stone, concrete, and greenery effortlessly.
The Benefits for You
1. Longevity
When you purchase a COR-TEN steel fire pit, you’re investing in a product that can last for decades. It won’t crumble like concrete, warp like cheaper metals, or peel like painted finishes.
2. Low Maintenance
Owning a COR-TEN fireplace is simple:
Remove ashes between burns.
Clean the glass occasionally with the ash-and-paper towel trick.
Grease the hinges once a year with the copper grease we provide.
That’s it. No sanding, repainting, or sealing required.
3. Designed for the Climate
Because COR-TEN’s protective barrier relies on wet-dry cycles, it’s perfectly suited to the PNW. From Seattle drizzle to salty Puget Sound air, your fireplace is built to thrive, not just survive.
4. Safety and Performance
COR-TEN fire pits aren’t just strong—they’re also stable and safe. With thick 3 mm steel walls, they contain heat effectively and minimize warping. Paired with RB73’s smart design, you get clean combustion, less smoke, and better draft.
5. Beauty That Lasts
The evolving patina means your fire pit only gets more attractive with age. It becomes a focal point of your backyard—a conversation starter as well as a source of warmth.
A Page from History: COR-TEN in Architecture & Art
COR-TEN steel isn’t just used in fire pits. It’s a material embraced by architects and artists worldwide.
John Deere World Headquarters (Illinois) features COR-TEN as its defining façade material.
Richard Serra’s sculptures, famous worldwide, use COR-TEN for its evolving textures and monumental durability.
Bridges, railways, and shipping containers rely on it for strength and longevity.
This pedigree makes COR-TEN not just a functional choice, but also a design-forward one. When you install a COR-TEN fireplace in your backyard, you’re bringing the same material trusted in world-class art and architecture into your home.
FAQs About COR-TEN Steel Fire Pits
How long does it take for the patina to form?
Usually 2–6 months, depending on exposure to rain, humidity, and sun.
Will COR-TEN steel rust away completely?
No—the patina is stable and protective. Once it forms, it slows corrosion dramatically.
Does COR-TEN steel stain patios or stone?
In the early stages, “rust water” runoff may stain lighter surfaces. We recommend placing fire pits on stone, gravel, or concrete during the patina phase.
Can I speed up the patina process?
Yes—lightly spraying with a salt or vinegar solution accelerates even rusting.
Is COR-TEN recyclable?
Absolutely. It’s 100% recyclable, making it a sustainable material choice.
Final Thoughts
When it comes to fire pits, material is everything. Cheaper options may last a few years, but COR-TEN steel fireplaces are built for a lifetime of fireside moments. Developed in the 1930s for industrial strength, COR-TEN has become a favorite of architects, artists, and now homeowners who want durability and beauty combined.
In the Pacific Northwest, where damp climates challenge most outdoor features, COR-TEN doesn’t just hold up—it thrives. It ages into a living work of art, blending rustic warmth with modern sophistication.
At Puget Sound Fire Pits, we’re proud to offer RB73’s COR-TEN steel fireplaces, designed to last, delivered and installed by our team, and supported for years of enjoyment.
🔥 Ready to bring home a fire pit that’s as timeless as it is durable? Explore our collection of handcrafted COR-TEN steel fire pits and fireplaces today.
