304 Stainless Steel
The most common form of 304 stainless steel is 18-8, or 18/8, stainless steel, which contains 18 percent chromium and 8 percent nickel. 304 can withstand corrosion from most oxidizing acids. That durability makes 304 easy to sanitize, and therefore ideal for kitchen and food handling applications.
However, 304 stainless steel is susceptible to corrosion from chloride solutions, or from saline food products. Chloride ions can create localized areas of corrosion, called “pitting,” which can spread beneath protective chromium barrier. Solutions with as little as 25 ppm of sodium chloride can begin to have a corrosive effect.
316 Stainless Steel
316 grade is the second-most common form of stainless steel. It has almost the same physical and mechanical properties as 304 stainless steel with slightly different percentages of chromium and nickel. 316 stainless steel incorporates about 2 to 3 percent molybdenum, the key to its enhanced ability to resist corrosive saline environments and industrial solvents. Due to its non-reactive qualities, 316 stainless steel is also used in food handling and the manufacture of medical surgical instruments.