Benefits of Corten Weathering Steel

Often used interchangeably, Corten and weathering steel are essentially the same material, offering enhanced strength and corrosion resistance. Corten steel is ideal for outdoor architectural and landscaping projects, exhibiting a patina (rust) that provides a protective layer from corrosion and atmospheric elements. Corten weathering steel’s aesthetic appeal includes the ability to be used in various applications without needing initial painting and maintenance upkeep.

What is Corten Steel?

Corten steel is a type of weathering steel often used in outdoor applications. While Corten and weathering steels are often interchangeable, COR-TEN® is a branded, trademarked, proprietary steel. COR reflects corrosion resistance, and TEN reflects tensile strength. Due to its name recognition, weathering steels are often called Corten steel. There are ASTM also specifications that reflect equivalent Corten types. 

Differentiating Corten Steel and Standard Steel

So, what’s unique about Corten steel? One of the main draws to Corten steel is its tactile feel. The texture and sight irregularity of Corten weathering steel is highly impressive. From a visual perspective, elaborate paints can replicate the look of Corten, but the weathered feel is entirely exclusive to Corten. Compared to galvanized steel with a tensile strength of 45-64 KSI, Corten steel boasts 68-78 KSI, allowing it to withstand greater forces before buckling or breaking.

Corten Weathering Steel Advantages

Some of the benefits associated with Corten edging and sheet steel include:Good strength

• Low maintenance
• Cost-effective
• Long term durability
• Ideal for heavy-duty applications
• Aesthetically appealing

Corten Steel and Rust

Although Corten steel is corrosion resistant, it is not entirely rust-proof. How long Corten steel lasts and how quickly the protective layer of rust develops depends mainly on climate and environmental factors.

• Generally, Corten steel will patina or rust within six months of atmospheric exposure. Most weathering steel types need wet/dry weather cycles to develop and oxidize.
• With the protective rust that provides corrosion resistance, Corten steel can last upwards of a few decades to over 100 years.
• To inhibit Corten to rust faster, salt water or a mixture of salt solutions mixed with vinegar and peroxide can speed up the rusting process

ASTM Weathering Steel Designations

ASTM weathering steels reflect specifications for low-alloy, high-strength structural steels. ASTM weathering steel options include: