Stainless steel used in architectural applications is generally from the Austenitic grades of Stainless Steel. There are two widely used grades, 316 and 304. For fasteners and other material that may be used in architectural use, 18-8 is also very common. All grades of Stainless Steel contains chromium (Cr), nickel (Ni), carbon (C), and iron. Grade 316 contains molybdenum as well as chromium (Cr), nickel (Ni), carbon (C), and iron.
A few general rules apply to the properties of the metal in regard to aesthetic value and architectural use.
- The higher the levels of carbon, the higher the strength and risk of corrosion
- The higher the levels of chromium, nickel and molybdenum, the higher the corrosion resistance
- Additional elements or change in elements can add corrosion resistance or strength, but rarely both.
When architectural applications will be exposed to the elements or in close proximity to the ocean, the recommended grade of stainless steel is 316L.