If you're sourcing stainless steel materials, understanding the differences between 304 and 316 stainless steel is essential for making cost-effective, performance-driven decisions. Here's a clear breakdown, supported by industry standards and data.
1. Overview & Applications
| Grade | Description | Typical Applications |
|---|---|---|
| 304 (EN 1.4301, UNS S30400) | Austenitic steel with 18% Cr, 8% Ni | Kitchen appliances, architectural panels, food equipment |
| 316 (EN 1.4401, UNS S31600) | 304 base + 2–3% Mo, higher Ni | Marine, chemical processing, medical, high-chloride environments |
2. Chemical Composition Comparison
| Grade | C | Si | Mn | P | S | N | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|---|
| 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 |
3. Corrosion Resistance
304 stainless steel offers excellent overall corrosion resistance in moderate conditions. However, it's prone to pitting and crevice corrosion in chloride-rich environments above ~150 ppm.
316 stainless steel significantly outperforms 304 due to the addition of molybdenum, delivering strong resistance against chloride-induced corrosion, making it ideal for marine, chemical, and medical environments .
4. 304 vs. 316 Stainless Steel: Mechanical & Thermal Properties
|
Property |
ASTM 304 |
ASTM 316 |
|---|---|---|
|
Tensile Strength |
515 MPa (min) |
515 MPa (min) |
|
Yield Strength (0.2%) |
205 MPa (min) |
205 MPa (min) |
|
Elongation (% in 50mm) |
40% |
40% |
|
Hardness (Brinell) |
201 HB (max) |
217 HB (max) |
|
Density |
8,000 kg/m³ |
8,000 kg/m³ |
|
Melting Point |
1400–1450°C |
1375–1400°C |
|
Temperature Tolerance |
||
|
Continuous Service |
870°C (max) |
925°C (max) |
|
Intermittent Service |
925°C |
870°C |
|
Cryogenic Use |
Safe down to -200°C |
Safe down to -200°C |
Are 304 and 316 non-magnetic?
A: Both are austenitic and non-magnetic when annealed; slight magnetism can appear after cold working.
Can both grades be welded easily?
A: Yes. 304 is slightly easier to weld; 316 also welds well but may benefit from post-weld annealing for maximum corrosion resistance.
5. Cost Considerations
Due to its higher nickel and molybdenum content, 316 stainless steel is typically priced 20-40% higher than 304 stainless steel. However, in corrosive or high-chloride environments, the long-term value of 316 stainless steel often outweighs the price difference.
Why Choose GNEE
At GNEE, we offer a wide range of 304 and 316 stainless steel products in the form of plates, tubes, and fittings. All products comply with ASTM/EN specifications and come with comprehensive test documentation (including EN 10204 3.1 mill certificates). We offer flexible supply, stocking standard sizes and supporting custom fabrication. We can also provide expert guidance to help you select the right material for your project environment and budget.es@gescosteel.com