Specifying Structural Sections
Stainless steel is an ideal choice for both visible and hidden structural sections in corrosive environments because of its corrosion resistance. The superior stiffness retention of austenitic stainless steels in fire relative to carbon steel means that fire protection may not be required in non-industrial buildings with lower fire temperatures. This combination of characteristics makes it possible to use uncoated stainless steel for many aesthetic structural applications.
There are, however, other reasons for its specification. Austenitic stainless steels in particular have much better impact resistance then carbon steel at ambient temperatures and still perform well at very low temperatures when carbon steel becomes quite brittle. These properties and its blast resistance make stainless steel an ideal choice for safety and security oriented applications. Please see IMOA’s Structural Design page for more resources.
Common stainless steel industry terminology can be confusing. Stainless steel suppliers commonly use “grade” to mean “alloy”. From a structural design perspective, “grade” means strength level and suppliers may be unaware of this terminology difference, which can cause confusion. Using specific yield and tensile strength levels and alloy names can avoid misunderstanding.
Finding Suppliers & Available Sizes
Stainless steel is available in the same product forms as carbon steel and aluminum but the range of stocked sizes is more limited because the market is much smaller. Any size and shape can be custom manufactured but that is generally more expensive and requires longer lead times. It is best to contact suppliers to determine commonly stocked sizes before starting design. This information can often be found on their websites and also for North America, via the links below:
Metals Service Center Institute Directory
SSINA Directories for Structural Service Centers and Manufacturers
Specifications & Guidelines
Always use the appropriate codes, specifications and design guides for stainless steel, including the stainless steel structural welding codes. We have a downloadable list for guidance.