When sourcing 304 series stainless steel, understanding the differences between 304, 304L, 304N, and 304H is crucial, especially for purchasing professionals who need to find the optimal balance between corrosion resistance, strength, and high-temperature performance. These austenitic stainless steels are widely used in chemical equipment, food processing, piping, and structural components, but their carbon and nitrogen content determines their specific applications.
304L Stainless Steel
The Chinese standard for 304L stainless steel is S30403. The carbon content of 304L stainless steel is reduced to below 0.03%. This not only improves the corrosion resistance of the stainless steel but also mitigates the sensitization and intergranular corrosion caused by carbide precipitation in the 450℃-860℃ range of 304 stainless steel, extending the service life of stainless steel welds. Furthermore, 304L stainless steel has better ductility than 304 stainless steel, thus it can replace 304 in many situations.
304N Stainless Steel
The basic properties of 304N stainless steel are similar to those of 304 stainless steel, but it is a nitrogen-reinforced stainless steel. Nitrogen is added to increase the strength of the stainless steel; therefore, 304N stainless steel is typically used in applications requiring high cold forming performance.
304H Stainless Steel
304H stainless steel is a high-carbon version of 304 stainless steel, with the Chinese standard number S30409. It has better high-temperature strength and oxidation resistance. The "H" in 304H represents high temperature; the high carbon content ensures its high-temperature strength. The carbon content of 304H stainless steel is not less than 0.04%.
Chemical Composition Comparison
| Grade | C | Cr | Ni | Mn | N | P | S |
|---|---|---|---|---|---|---|---|
| 304 | ≤0.08% | 18–20% | 8–10.5% | ≤2% | ≤0.10% | ≤0.045% | ≤0.03% |
| 304L | ≤0.03% | 18–20% | 8–10.5% | ≤2% | ≤0.10% | ≤0.045% | ≤0.03% |
| 304N | ≤0.08% | 18–20% | 8–10.5% | ≤2% | 0.10–0.16% | ≤0.045% | ≤0.03% |
| 304H | 0.04–0.10% | 18–20% | 8–10.5% | ≤2% | ≤0.10% | ≤0.045% | ≤0.03% |
Mechanical Properties Comparison
| Property | 304 | 304L | 304N | 304H |
|---|---|---|---|---|
| Tensile Strength | 520–720 MPa | 485–700 MPa | 550–750 MPa | 600–780 MPa |
| Yield Strength | 205–310 MPa | 170–275 MPa | 300–400 MPa | 300–420 MPa |
| Elongation | 40–60% | 45–60% | 35–50% | 30–45% |
| Hardness (HRB) | 70–90 | 70–85 | 75–95 | 75–95 |
| Corrosion Resistance | Excellent | Excellent | Excellent | Very good |
Key Takeaways:
304L is preferred for welded constructions due to low carbon.
304N offers higher mechanical strength due to nitrogen addition.
304H is ideal for high-temperature applications, maintaining strength at 500–800°C.
Differences between 304, 304L, 304N, 304H ：price
The price of 304 stainless steel ranges from USD 2.50–3.20 per kg, with 304L slightly higher at USD 2.60–3.40 per kg due to specialized low-carbon production. 304N and 304H are generally 10–15% more expensive because of nitrogen or high-carbon content.
GNEE offers a wide range of high-quality 304 stainless steel products at wholesale prices. As a purchasing manager, you can find the best deals to meet your industry needs. We offer various grades of stainless steel sheets to meet your requirements. We have a reliable supply and cost-effective solutions that you can trust.
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What is the difference between 304L and 304H?
The main difference is carbon content, which affects their primary uses: 304L has low carbon to prevent corrosion after welding, making it ideal for welded applications, while 304H has higher carbon for increased strength at high temperatures, making it suitable for use in boilers and heat exchangers.
What is the difference between 304 and 304N?
Why choose 304N over 304 or 304L? 304N adds 0.10–0.16 wt% nitrogen, boosting yield strength by ~20 % (to ≈260 MPa), refining grain size, and raising pitting resistance (PREN ≈ 20 vs. ≈ 18) for better performance in chloride‐rich or cryogenic environments.
What is the difference between 304L and 304LN?
304LN was originally developed as a higher strength version of 304L using nitrogen. However, the increase in strength is only modest and duplex grades are now mostly used for this purpose. The grade is now used in specialised applications where a very low magnetic response is needed.