When it comes to the selection of stainless steel for your project there are two of the most popular grades 316 and 304. Both of them are strong and resistant to corrosion but due to their distinct characteristics, they are used in different fields. That is why it is essential to know all these differences in order to choose the grade that will be suitable for your project. Let’s take a closer look at 316 and 304 stainless steel to help you decide which is ideal for your specific needs.
Difference Between SS 316 vs. SS 304
Composition
- 316 Stainless Steel and 304 SS are austenitic stainless steels which contain high quantities of chromium and nickel. However, the main difference lies in their composition:
- 304 Stainless Steel: The stainless steel 304 contains 18-20% chromium and 8-10.5% nickel and is rust and corrosion resistant.
Corrosion Resistance
- 316 SS Has chromium content of 16-18%, nickel of 10-14% and a little more than 2% to 3% of molybdenum. This addition of molybdenum improves on the corrosion resistance of 316 in the presence of chlorides and other aggressive chemicals making it a better material for use in difficult conditions.
- Due to this molybdenum content the 316 is often referred to as the ‘marine’ grade stainless steel and is used in marine, chemical processing and industrial applications where there is likely to be exposure to salt water or other corrosive agents. SS 304 has better overall use and does not have to withstand as much stress from the environment.
Strength and Durability
Both grades provide good strength and excellent resistance to wear, heat and various forms of mechanical stress. However:
- 304 Stainless Steel is easier to shape and manipulate, thus it is ideal for use in situations that need some variety in the manufacturing processes.
- 316 Stainless Steel is somewhat more difficult to form, but it offers higher strength in severe applications, the reason why it is used in applications that require high endurance and resistance to pitting and crevice corrosion.
Applications
- 304 Stainless Steel Applications: Since it’s inexpensive and can be used in many different ways, 304 is used in situations where severe chemical durability is not a necessity. Common uses include:
- Kitchen equipment
- Food processing surfaces
- Automobiles and Construction Industry.
- Manufacturing vessels and equipment
- 316 Stainless Steel Applications: In applications that include the use of aggressive chemicals, sea water or areas of high chloride content, 316 is normally the material of choice. It’s commonly used in:
- Marine and coastal uses
- Chemical processing equipment
- Medical implants and surgical equipment
- High-temperature environments
Cost Considerations
Generally, 316 stainless steel is more expensive than 304 due to its added molybdenum content and improved corrosion resistance. If the project doesn’t come in contact with corrosive substances or conditions, one can use SS 304, getting a better quality product at an affordable price. If an application demands superior performance, there is a need to spend more on 316 to avoid future expenses of maintenance or replacement.
Which Grade Should You Choose?
The decision between 304 and 316 stainless steel depends on the nature of your application. If corrosion resistance is an issue, especially chloride or chemicals, ss 316 is the best choice. On the other hand, if cost per piece and general sturdiness are of paramount importance, 304 stainless steel is a good and all-around material. Picking the right stainless steel grade for your project will then guarantee durability in terms of quality and cost. From the flexibility that is provided by 304 to the increased corrosion capability of 316, the two grades provide the strength and quality that are associated with the stainless steel materials.
