Structural stainless steel was first used for larger applications in the United States in the mid 1960’s. In the early 2000’s, Stainless Structurals America opened and brought the entire array of the A6 carbon steel structural platform to the market in stainless steel. With domestic production making these products readily available, structural stainless steel has increased in popularity and has become a desirable alternative to other metals used for structural elements in construction and many other industries.
Before discussing the basic uses of structural stainless steel, it is important to address how stainless steel actually works. Stainless steel is exactly what the name implies. In general, stainless steel is a low carbon steel that contains at least 10.5% chromium. Chromium is the element that gives stainless steel its corrosion resistance properties by providing a protective passive film at the surface level to prevent rust and allows it to self-repair in the presence of oxygen. Corrosion resistance can be increased by choosing stainless steel alloys which are higher in chromium, higher in nickel and that have molybdenum or even nitrogen added. These elements improve the resistance to pitting and offer better mechanical properties. It also important to point out that stainless steel is 100% recyclable making it one of the most environmentally friendly materials used in construction.
The Many Uses of Stainless Structural Profiles
The corrosion resistance of stainless steel is the biggest reason why the most popular uses of structural stainless involve those in industrial applications. Industries such as food processing, wastewater, chemical, oil & gas, marine, transportation and more are hot beds for corrosion making stainless steel the material of choice for structural components. Stainless steel is also a great choice where strength and durability are key factors. Projects where strength and corrosion resistance are required are perfect for the duplex stainless steel alloys. The improved mechanical properties of duplex allows engineers to design with lighter profiles without sacrificing strength, which reduces the weight and achieves cost reductions.
Structural stainless steel is not just an industrial product. The aesthetics of stainless structural shapes make these very popular in architectural applications. Many architects and engineers are opting for exposed structural elements such as entryways and curtain walls that make bold statements and allow for open floor plans. Structural stainless can be used for modern design elements such as skylights and sunscreens. Using structural stainless steel for exposed structures is no problem because they easily meet AESS guidelines. Stainless Steel is also fire and blast resistant making it a great product for security and safety features. This includes structural supports, gates, bollards, and more.
Specification and Selection
Choosing the proper alloy of stainless steel is key for architects and engineers when designing with stainless steel. Corrosion resistance should be the first consideration. You want to make sure you choose a grade of stainless that will provide the proper corrosion resistance for the application. Type 316/L is a very popular choice for exterior or marine applications due to its higher corrosion resistance. The second decision should be the mechanical and physical properties required for the application. Do you need a higher strength product? If so, duplex stainless steel would be an appropriate choice. A great resource to help with material selection is the AISC Design Guide #27. This guide deals specifically with the use of structural stainless steel and is available for download from our support page.
Once the best material for the application has been chosen, the architect or engineer must then specify that material in project drawings and documents. Specifications can be done by the material shape designation or also the actual material standard. For structural stainless steel, the standard would either be ASTM A276 for hot rolled sections or ASTM A1069 for laser-fused sections. The majority of structural stainless steel shapes would fall under the A1069 designation. One benefit of using the new ASTM A1069 is you can select strength categories as well. The general rule of thumb is to use the design guide for material selection and the ASTM for specification.
Resources and Availability
Both the Support Page and Product Catalog found on our website are full of resources for engineers, architects, fabricators, and distributors. Section properties developed specifically for sharp cornered profiles and Revit files for beams, channels, angles, tees and hollow structural steel are available to download as well as our product information and brochures. Our team is here to help with any questions you may have. Please contact us or chat with us today so we can assist with your next stainless steel design.