Frequently Asked Questions

General Questions

What is the difference between Type 304 and Type 316 stainless steel?

The chemistries of these stainless steels are similar but Type 316 contains a molybdenum addition. The molybdenum gives Type 316 resistance to chlorides and improved resistance to urban and industrial pollution. If an application is within five to ten miles of a large salt-water body or exposed to deicing salts, Type 316 is often the most cost effective choice if corrosion-free performance is desired. Type 316 should also be considered if the location has low to moderate industrial pollution exposure or has high levels of urban pollution. Additional information about stainless steel selection can be found in the IMOA brochure Which Stainless Steel Should Be Specified for Exterior Applications and the Nickel Institute brochure 'Stainless Steels in Architecture, Building, and Construction: Guidelines for Corrosion Prevention'

What is the difference between 304 and 304L (or 316 and 316L)?

The “L” indicates low carbon.The chemistry requirements for Types 304 and 304L are identical except that Type 304L must have lower carbon levels.The low carbon version of the stainless steel should be specified if the design requires welding sections heavier than about 0.25 inches (6 mm) and the weld area will be exposed to a corrosive environment.Low carbon levels reduce the risk of sensitization and improve weld corrosion resistance.