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Stainless steel is an extremely popular and valuable metal alloy that delivers numerous beneficial features to nearly unlimited applications worldwide. Both 304 and 316 grade stainless steel products possess some of the best corrosion resistance within the world of metal. Each alloy grade maintains its unique properties, providing variations that allow 316 and 304 stainless steels for similar and individually unique industrial applications.
What is Stainless Steel?
Stainless steel is one of the most popular and well-recognized metals, known for its attractive appearance, low maintenance requirements, and resistance to corrosion and staining. Unlike regular carbon steel, stainless steel does not readily corrode in the presence of water. When the strength and toughness of steel are required, along with the need for corrosion resistance, stainless is often the answer. All types of stainless steel contain at least 10% chromium by weight.
High Performance 316 Stainless Steel
Premium grade 316 stainless steel comprises iron with added chromium, nickel, silicon, manganese, carbon, and molybdenum properties. The added molybdenum content within 316 allows for enhanced corrosion resistance and protection against acids and chlorides, allowing it to be used in all types of marine applications.Stainless Steel 316 Advantages:
- Increased corrosion resistance over 304
- Good strength at high temperatures
- Good resistance to pitting in chloride ion solutions
- Effective in acidic environments
- Enhanced long-term value
316 Stainless Steel Applications:
- Foodservice equipment
- Medical equipment & devices
- Marine environment structural steel
- High alkali & acid environments
- Coastal regions
- Commercial kitchen surfaces
Stainless Steel 316 Chemical Composition
The chemical composition of 316 stainless steel includes:| Element | Composition % |
| Chromium | 16-18 |
| Nickel | 10-14 |
| Molybdenum | 2-3 |
| Manganese | 2 (Max) |
| Iron | Balance |
Austenitic 304 Stainless Steel
Regarded as the most common austenitic stainless steel, 304 displays a nickel and chromium content that provides good corrosion resistance. Stainless steel 304 is also easy to sanitize, making it ideal for a wide range of applications within the food production industry. Due to its minimum of 18% chromium and 8% nickel, type 304 stainless steel is often referred to as 18-8 stainless steel. It is available in various forms and can be easily formed and fabricated.Stainless Steel 304 Advantages:
- Excellent corrosion resistance
- Resists organic chemicals
- Impact-resistant
- Enhanced aesthetic value
- Easily recyclable
304 Stainless Steel Applications:
- Appliances
- Storage tanks
- Indoor electrical enclosures
- Kitchen equipment
- Automotive trim
Stainless Steel 304 Chemical Composition
The chemical composition of 304 stainless steel includes:
| Element | Composition % |
| Chromium | 18 |
| Nickel | 8 |
| Manganese | 2 (Max) |
| Iron | Balance |
Comparing 316 Stainless Steel & 304 Stainless Steels
The most fundamental difference between grade 304 and grade 316 stainless steel is that 316 tends to have more nickel and a bit of molybdenum in the mix. The general mechanical properties of the two metals are primarily comparable. The following table compares some of the most valuable qualities of 304 and 316 SS:
| SS Type | 0.2% Yield Strength/RpO/MPa | Tensile Strength/Rm/MPa | Brinell Hardness/HB Max |
| 316 SS | 240 | 530-680 | 120-180 |
| 304 SS | 230 | 540-750 | 130-180 |
316 vs 304 Stainless Steel Chemical Resistance Qualities
Grade 316 stainless steel’s high nickel content and inclusion of molybdenum allow grade 316 stainless steel to have better chemical resistance than 304 stainless steel. Its ability to resist acids and chlorides, including salt, makes grade 316 ideal for chemical processing and marine applications.Differentiating the Melting Points of 316 & 304 Stainless Steel
The melting point of grade 304 stainless steel is a bit higher than that of grade 316. The melting range of 316 is 2,500 °F – 2,550 °F (1,371 °C – 1,399 °C), roughly 50 to 100 degrees Fahrenheit lower than the melting point of grade 304 stainless steel.Stainless Steel 304 & 316 Machining Qualities
When it comes to machinability, grade 304 is much easier to machine than 316 grade stainless steel. Since it is less expensive and easier to fabricate, stainless steel 304 alloy is the most widely used austenitic stainless steel in the world. Special tools are required to properly machine stainless steel alloy 316, which means that 316 is often reserved exclusively for applications that require its unique properties.Does Stainless Steel Rust?
Due to its chemical nature and self-healing capabilities, stainless steel does not rust. The elements within stainless steel interact with the oxygen in the air to form a protective layer that shields the iron within the stainless steel from oxidation, which leads to rust. Since type 316 stainless steel contains molybdenum, its corrosion-resistant properties exceed those of 304.
316 Stainless Steel vs 304 Stainless Steel: Which Should you Choose?
Even though stainless steel 304 has a higher melting point, grade 316 has better resistance to chemicals and chlorides (like salt) than grade 304 stainless steel. Regarding applications with chlorinated solutions or exposure to salt, grade 316 stainless steel is considered superior.When comparing 304 versus 316 stainless steels, it is essential to note that 316 is regarded as the superior alloy of the two grades. However, with that designation comes an increased price point and performance advantages that, depending on your application, may or may not be worth the extra cost. The stainless steel that is best for your project will depend on specification requirements.
