304 stainless steel and 316 stainless steel
The difference between 304 stainless steel and 316 stainless steel
Both 304 and 316 stainless steel are austenitic stainless steels, but 316 has superior corrosion resistance due to the addition of molybdenum. 304 stainless steel is more cost-effective for general use, while 316 stainless steel is more suitable for harsh environments such as marine or chemical applications.
What are the disadvantages of 316 stainless steel?
While 316 stainless steel offers excellent corrosion resistance, it does have some drawbacks. The main drawbacks are its higher cost compared to other grades, such as 304, and its poorer machinability and formability. It is also susceptible to stress corrosion cracking in certain harsh environments.
304 vs. 316 Stainless Steel Properties Comparison
As austenitic materials, they exhibit similar properties. The properties of 304 and 316 stainless steel are identical or nearly identical, due to their similar chemical compositions. For example, despite the addition of molybdenum to 316 stainless steel, their densities are generally the same. However, molybdenum has a relatively low atomic weight, so its effect on density is minimal.
The table below lists the key differences between the two grades, including density, melting point (melting range for 316 grade), elastic modulus, electrical resistivity, thermal conductivity, and shear modulus.
| Property | 304 | 316 |
|---|---|---|
| Density | 0.289 lb/in³ | 0.289 lb/in³ |
| Melting Point | 2642°F | 2500°F – 2550°F |
| Modulus of Elasticity | 28,000 ksi | 28,000 ksi |
| Electrical Resistivity | 0.72 × 10⁻⁶ Ω·m | 0.74 × 10⁻⁶ Ω·m |
| Thermal Conductivity | 112 BTU·in/(hr·ft²·°F) | 113 BTU·in/(hr·ft²·°F) |
| Shear Modulus | 11,200 ksi | 11,8931 ksi |
304 vs. 316 stainless steel: a comparison
| Element | 304 stainless steel % | 316 stainless steel % |
|---|---|---|
| Carbon | 0.07 | 0.07 |
| Chromium | 18.0 – 19.5 | 16.5 – 18.5 |
| Nickel | 8.0 – 10.5 | 10.0 – 13.0 |
| Silicon | 1.00 | 1.00 |
| Manganese | 2.00 | 2.00 |
| Phosphorous | 0.045 | 0.045 |
| Sulfur | 0.015 | 0.015 |
| Nitrogen | 0.10 | 0.10 |
| Molybdenum | - | 2.0 – 2.5 |
304 vs. 316 stainless steel strength
In terms of mechanical strength, 316 stainless steel is generally considered stronger than 304 stainless steel. This is also attributed to the molybdenum content in 316 stainless steel. As a result, 316 stainless steel generally has better mechanical properties. The yield strength and tensile strength of both can vary depending on the manufacturing process and related conditions, but in general, 316 stainless steel has a higher tensile strength than 304 stainless steel.
| Mechanical properties | 304 stainless steel | 316 stainless steel |
|---|---|---|
| Ultimate Tensile Strength | 73200 psi | 79800 psi |
| Tensile Yield Strength | 31200 psi | 34800 psi |
| Hardness (Rockwell B) | 70 | 80 |
| Elongation at break | 70% | 60% |
304 vs. 316 stainless steel differences
| Characteristics | 304 stainless steel | 316 stainless steel |
|---|---|---|
| Corrosion resistance | Excellent | Even better |
| Magnetic | No | No |
| Weldability | High | Good |
| Hardens during cold forming | Yes | Yes |
| Formability | Very good | Good |
| Machinability (annealed) | Fair, but better than 316 | Fair |
| Resists elevated temperatures | High | High |
| Maximum intermittent service temperature | 1562°F | 1562°F |
Gnee Steel specializes in the production and sale of a wide range of stainless steel products, including 304, 316, 321, 904, 904L, 2205 Duplex, 2205 Duplex, and 316L stainless steel. Gnee Steel's products are widely used in the kitchen, aerospace, chemical, power, automotive, and nuclear energy sectors. We also provide custom stainless steel solutions tailored to customer needs. For stainless steel pricing or custom alloy solutions, please email ru@gneesteelgroup.com for a quote.
