When it comes to choosing the right material for food processing equipment, stainless steel is often the material of choice due to its strength, corrosion resistance, and durability. Among the various grades of stainless steel, 316 and 304 are the two most popular options. But how do you decide which one is better for your food processing equipment? Let’s compare both to help you make an informed decision.
What is Stainless Steel 304?
Stainless Steel 304 is an austenitic stainless steel containing 18% chromium and 8% nickel, also known as the “18-8” stainless steel 304. It is very famous due to its best attributes, such as its high corrosion, excellent endurance, and versatility, and it is used in various equipment such as kitchen utensils, food preparation tools, and industries.
What is Stainless Steel 316?
Stainless Steel 316 is an austenitic stainless steel that comprises 16-18% chromium, 10-14% nickel and 2-3% molybdenum. The presence of molybdenum increases its corrosion resistance,, especially to chloride and acidic solutions, and therefore, it is used in marine, chemical and food processing industries.
Corrosion Resistance
Stainless Steel 304
- SS 304 is safe for contact with most foods and beverages, ensuring food-grade safety and providing adequate resistance at a lower cost than higher grades.
- It is resistant to most oxidising acids and does not rust in food processing environments.
- However, due to chloride, 302 stainless steel is vulnerable to pitting and is therefore unsuitable for use in areas with salty or briny water.
Stainless Steel 316
- Corrosion resistance remains effective under elevated temperatures in food and industrial processes.
- Stainless steel 316 is ideal for sea food industries or when handling acidic products such as oranges or tomatoes.
Thus 316 SS is the better choice for use in saline or acidic conditions because of its higher levels of corrosion resistance.
Durability and Strength
Stainless Steel 304
- 304 SS provides great wear resistance and can withstand various mechanical loads.
- It is quite strong tensile and does not deteriorate even when washed frequently or subjected to rough handling.
Stainless Steel 316
- SS 316 has better tensile strength because of the presence of molybdenum.
- It is ideal for applications where productivity will be exposed to harsher conditions for longer.
Both grades are very strong, but 316 performs slightly better in severe conditions.
Hygiene and Cleanability
- 304 and 316 are both non–porous, have a shiny surface and are easy to clean and disinfect to avoid bacterial formation.
- The two grades are food-grade compliant, thus making them appropriate for hygienic use.
Thus, they have little difference; both grades are perfect for keeping food safe.
Temperature Resistance
Stainless Steel 304
- It is resistant to heat up to 870°C and may start to deform above this temperature.
- Stainless steel 304 is appropriate for a wide range of food processing applications requiring moderate heat.
Stainless Steel 316
- SS 316 has high operating efficiency in high or low temperatures and the capacity to handle long-term exposure to high or low temperatures.
Thus, 316 is better suited for applications exposed to high or low temperatures.
Cost Considerations
Stainless Steel 304
- It is more accessible and cheaper than the previous method.
- 304 SS is suitable for most applications where food products are processed but not for conditions involving aggressive chemicals or severe conditions.
Stainless Steel 316
- Stainless steel 316 is costlier than the standard austenitic stainless steel because of molybdenum and higher nickel content.
- The investment is warranted for applications that are most demanding in corrosion protection.
304 is used for most general purpose food handling applications due to its relatively low cost, while 316 is used in more specific applications where the cost of the material can be justified.
Uses in the food industry
Stainless Steel 304
- It is suitable for food preparation equipment that does not come into direct contact with food products, such as containers, countertops and sinks.
- 304 is recommended for use in areas with little or no contact with salt or other chemicals.
Stainless Steel 316
- 316 SS is applied where equipment is exposed to salty water or foods containing high levels of sodium chloride or where equipment comes into contact with pickles, fruits and other acidic foods.
- It is found in industries that use food products from the seas and environments where high levels of corrosion resistance are needed.
Conclusion
Stainless Steel 304 and Stainless Steel 316 are very reliable materials, and they are applied in different areas of the industry mainly because they offer differences that could meet different project requirements. Stainless Steel 304 is widely used for its stability, cost, durability, and exceptional corrosion resistance ability in moderate conditions. It is suitable for normal food processing industries, kitchen utensils and other general industrial applications. At the same time, 316 is a premium grade of stainless steel which is more resistant to corrosive attack than grade 304, especially in chloride, acidic or high temperature environments. It is difficult for saltwater and acids to affect it. Hence, it can be used in areas where the conditions are worse, such as in the marine chemical and food industries, due to the hygienic nature of the environment.
