SUS304H Stainless Steel: Chemical Composition, Strength
Leave a message
what is SUS304H Stainless Steel?
SUS304H is an austenitic stainless steel grade, essentially a high-carbon version of standard 304 stainless steel. The "H" indicates a higher carbon content (0.04-0.10% C), which improves strength, particularly creep resistance and yield strength at high temperatures (up to approximately 1500°F/815°C). It is highly suitable for high-temperature applications such as boilers, heat exchangers, and petrochemical processing equipment.
What does the H stand for in 304H?
The "H" in 304H stands for "High" carbon content. 304H must contain not less than 0.04 percent carbon, nor more than 0.10 percent. The higher carbon content of 304H increases its strength, so the ASTM tensile and yield strength of 304H is greater than 304L.
Click to view the 304H stainless steel data sheet
What is the chemical composition of SS 304H?
304H stainless steel is an austenitic steel with key elements: 18-20% Chromium (Cr), 8-10.5% Nickel (Ni), and a higher carbon content of 0.04-0.10% (compared to 304/304L), which boosts its high-temperature strength and creep resistance.
Chemical Composition of Grade 304H Stainless Steel
| UNS NO | Grade | C | Si | Mn | P | S | Cr | Mo | Ni | N |
| S30409 | 304H | 0.04/0.10 | 0.75 | 2.00 | 0.045 | 0.030 | 18.00/20.00 | - | 8.00/10.50 | 0.10 |
Mechanical Properties of Grade 304H Stainless Steel
| UNS No | Grade | Proof Stress 0.2% (MPa) |
Tensile Strength (MPa) |
Elongation A5(%) |
Hardness Max | |
| HB | HRB | |||||
| S30409 | 304H | 205 | 515 | 40 | 201 | 92 |
What are the properties of 304H material?
Alloy 304/304H has general corrosion resistance similar to 304/304L. It resists atmospheric corrosion, as well as, moderately oxidizing and reducing environments. However, because of its high carbon content, Alloy 304/304H is subject to carbide precipitation in the heat affected zone of welds.
What is the temperature limit for 304H stainless steel?
Dual certified 304/304H is used as a material of construction up to 1500°F. Slight scaling begins at about 1200°F. 304/304H meets a 0.04% minimum carbon content and has a grain size of ASTM 7 or coarser.
What is the strength of SUS304H stainless steel?
SUS304H stainless steel offers good strength, typically with a minimum tensile strength of ≥ 515 MPa (75 ksi) and a minimum yield strength (0.2% offset) of ≥ 205 MPa (30 ksi), along with ≥ 40% elongation, designed for high-temperature strength retention in applications like boiler tubes, maintaining flexibility and stability under heat.
Applications of SUS 304H Stainless Steel
304H stainless steel is commonly found in the oil refining, gas and chemical industry and is used in industrial boilers, pressure vessels, heat exchangers, pipelines and condensers. The material is also used throughout the power generation industry.
What is the Difference Between 304L and 304H Stainless Steel?
The main difference between 304 stainless steel and 304H stainless steel lies in their carbon content. 304H is a high-carbon version of standard 304 stainless steel (with a carbon content of 0.04-0.10%), while standard 304 has a carbon content of ≤0.08%. Therefore, 304H offers superior high-temperature strength and creep resistance (e.g., for use in heat exchangers and boilers), while standard 304 provides good general corrosion resistance and formability, making it suitable for everyday items (e.g., cookware, sinks).
GNEE currently has SUS 304H (UNS S30409) products in stock, including: plates, sheets, coils, strips, tubes, bars, and wires. In addition, we offer a variety of surface finishes for you to choose from, such as: No. 1, 2B, 2D, BA, No. 3, No. 4, HL, No. 8, sandblasting, etc.
We guarantee 100% quality. We will never deliver any defective products to our customers. Please contact us to customize your required product specifications, including shape, condition, surface treatment, and processing techniques.
