Grade 304 is the most widely used stainless steel and contains approximately 18% chromium and 8% nickel. It offers excellent corrosion resistance in most environments and is suitable for a broad range of architectural, structural and fabrication applications. Grade 316 contains an additional 2–3% molybdenum, which significantly improves resistance to chloride-induced corrosion — making it the correct specification for coastal, marine, chemical processing and food production environments where 304 may be susceptible to pitting.
As a general rule of thumb: specify 304 for inland and urban environments; specify 316 within approximately 5km of the coast or wherever the material will be in contact with salt water, chlorinated water, de-icing salts or corrosive chemicals.
