To most people, telling the differences between one grade of stainless steel and another can be difficult and easy to miss. However, differentiating between stainless steel alloys is essential for manufacturers as different grades have different characteristics. Two of the more commonly used grades of austenitic stainless steel are grades 304 and 316. To help you determine which grade is right for you, we will examine the difference between 304 and 316 stainless steel.
304 Stainless Steel
Grade 304 stainless steel, with its chromium-nickel content and low carbon, is the most versatile and widely used of the austenitic stainless steels. Its alloys are all modifications of the 18% chromium, 8% nickel austenitic alloy. It is a highly resistant to oxidation, corrosion, and offers good durability.
With good formability, grade 304 stainless steel provides ease of fabrication, sanitization and cleaning, with a variety of finishes and appearances with the use of stainless steel pipes, stainless steel plates, stainless steel round bars etc.
Common applications of 304 stainless steel include:
- Appliances such as refrigerators and dishwashers
- Commercial food processing equipment
- Heat exchangers
- Structures in environments that would corrode standard carbon steel.
316 Stainless Steel
Grade 316 is a popular austenitic stainless steel alloy with superior strength, corrosion resistance, and high concentrations of chromium and nickel. Grade 316 contains molybdenum, which improves the alloy’s resistance to acids, alkalis, and chloride pitting. Grade 316 is durable, easily fabricated and possesses good weldability.
Grade 316 stainless steel is often considered one of the most suitable choices when selecting an austenitic stainless steel for marine applications, with the use of stainless steel beams, stainless steel angle bars, stainless steel flat bars etc.
Other common applications of grade 316 stainless steel include:
- Chemical processing and storage equipment.
- Refinery equipment
- Medical devices
- Marine environments, especially those with chlorides present
What’s the Difference Between Grade 304 and Grade 316 Stainless Steel?
|304||0.07||1.00||2.00||0.045||0.015||0.10||17.5 – 19.5||8.0 – 10.5||–|
|316||0.07||1.00||2.00||0.045||0.015||0.10||16.5 – 18.5||10.0 – 13.0||2.0 – 2.5|
1. Chemical Composition
The most basic difference between grade 304 and grade 316 stainless steels is the chemical composition. Grade 316 tends to have more nickel and a bit of molybdenum in the mix. The general mechanical properties of the two metals are mostly comparable.
The addition of nickel and molybdenum makes grade 316 stainless steel a more expensive alloy than grade 304 stainless steel per ounce of material.
3. Properties and Applications
Due to the addition of molybdenum, grade 316 stainless steel is more corrosion resistant than grade 304 stainless steel. This reduces pitting from chemical environments and allows grade 316 stainless steel to be used in highly acidic and caustic environments that would corrode the metal. For example, grade 316 stainless steel can withstand corrosive solutions and applications such as vapour degreasing and other cleaning processes.
These properties also make grade 316 stainless steel ideal for pharmaceutical and medical applications. Since sterilization processes in these industries require strong disinfectants and high temperatures to prevent contamination, a resistant alloy such as grade 316 stainless steel is the perfect medium.