SS 304H Material Properties Tensile Strength and Yield

SS 304H Material Properties: Tensile Strength and Yield

At Gangsteel, a leading manufacturer and exporter of stainless steel products, we supply premium SS 304H material plates compliant with ASME SA 240 and ASTM A240 standards. SS 304H material, also known as AISI 304H, UNS S30409, or EN 1.4948, is a high-carbon austenitic stainless steel optimized for high-temperature strength and creep resistance up to 1500°F (815°C). This guide focuses on the tensile strength and yield strength properties of SS 304H material, alongside other key mechanical and physical properties, for applications like boilers, heat exchangers, and SA 240 GR 304 pipe. For inquiries, contact us at admin@gangsteel.com or explore our ASME SA240 Stainless sheet offerings.

Tensile Strength of SS 304H Material

The tensile strength of SS 304H material is the maximum stress it can withstand before fracturing. For annealed plates (8-75 mm thick), the minimum tensile strength is:

• Tensile Strength: 515 MPa (75 ksi)

This strength is comparable to SA 240 GR 304 (515 MPa) but higher than SA 240 GR 304L (485 MPa), due to the higher carbon content (0.04-0.10%) in SS 304H, which enhances performance at elevated temperatures. At 1000°F (538°C), SS 304H maintains an allowable stress of 25.5 ksi, outperforming 304 (18.6 ksi) and 304L (14.9 ksi), making it ideal for high-temperature structural applications like sa240 gr 304h plates.

Yield Strength of SS 304H Material

The yield strength of SS 304H material is the stress at which plastic deformation begins (0.2% offset). For annealed plates, the minimum yield strength is:

• Yield Strength: 205 MPa (30 ksi)

This is higher than SA 240 GR 304L (170 MPa) and matches SA 240 GR 304, ensuring better resistance to deformation under load, especially at high temperatures. The increased carbon content strengthens the material’s creep resistance, critical for applications like boilers and heat exchangers. For comparison, see sa240 gr 304 and sa240 gr 304l.

Other Mechanical Properties

Additional mechanical properties of SS 304H material include:

• Elongation: 40% ensures excellent formability, suitable for applications like plate 2 mm SUS 304.
• Hardness: ≤201 HB allows easy machining, similar to other 304 grades.
• Cold-Working: Can increase tensile strength up to 900 MPa, reducing ductility for high-strength needs.

Physical Properties of SS 304H Material

The physical properties of SS 304H material support its high-temperature performance:

• Density: 8.00 g/cm³, ideal for lightweight designs (e.g., a 1m x 1m x 3mm plate weighs ~24 kg).
• Melting Point: 1400-1450°C, suitable for high-temperature processing.
• Thermal Conductivity: 16.2 W/m·K at 100°C, moderate for heat transfer.
• Coefficient of Thermal Expansion: 17.2 × 10⁻⁶/K (20-100°C), stable across temperatures.
• Electrical Resistivity: 0.72 × 10⁻⁶ Ω·m, good for non-conductive applications.
• Service Temperature:
  • Continuous: Up to 1500°F (815°C) with excellent creep resistance.
  • Intermittent: Up to 1600°F (871°C).
  • Scaling Onset: ~1200°F (649°C).
  • Sensitization Range: Avoid 797°F-1580°F (425°C-860°C) to prevent carbide precipitation.

These properties make SS 304H material ideal for high-heat environments, unlike ferritic grades like sa240 gr 430.

Corrosion Resistance of SS 304H Material

SS 304H materialoffers corrosion resistance similar to 304:

• Excellent in atmospheric conditions, freshwater, and mild acids (food-grade).
• Outperforms SS204 vs SS 304 due to higher nickel (8-10.5%).
• Higher carbon (0.04-0.10%) increases sensitization risk in weld zones (797°F-1580°F), requiring annealing. Less chloride-resistant than sa240 gr 316l.

Weldability of SS 304H Material

Weldability is fair using ER308H fillers. Higher carbon risks sensitization, necessitating low heat input (<2.0 kJ/mm) or post-weld annealing (1870-2100°F). For better weldability, see sa240 gr 304l or sa240 gr 321.

Applications of SS 304H Material

SS 304H materialis used in:

• Boilers and pressure vessels (steam drums, headers).
• Heat exchangers (tubes, shells).
• Power generation (superheaters, reheaters).
• Chemical processing (vessels, SA 240 GR 304 pipe).
• High-temperature piping and fittings.

For chloride-heavy environments, explore sa240 gr 317l.

Pricing and Availability at Gangsteel

As of October 19, 2025, SS 304H material plate prices (2B finish, 3-6mm) range from $1.60-$3.50/kg globally. Gangsteel offers $1.60/kg FOB (MOQ 1 ton) for sa240 gr 304h plates, including custom sizes like plate 2 mm SUS 304. Contact admin@gangsteel.com or visit astm a 240 stainless plate.

FAQ on SS 304H Material Properties

What is the tensile strength of SS 304H material?

The minimum tensile strength is 515 MPa (75 ksi), ensuring robust performance before fracture, especially at high temperatures up to 1500°F (815°C).

What is the yield strength of SS 304H material?

The minimum yield strength is 205 MPa (30 ksi), providing better resistance to deformation than 304L (170 MPa), ideal for high-temperature structural loads.

How does SS 304H compare to 304L in tensile and yield strength?

SS 304H (515 MPa tensile, 205 MPa yield) is stronger than 304L (485 MPa tensile, 170 MPa yield) due to higher carbon, especially in creep resistance at elevated temperatures.

Why is SS 304H suitable for high-temperature applications?

Its high carbon content (0.04-0.10%) enhances creep and rupture strength, with an allowable stress of 25.5 ksi at 1000°F, making it ideal for boilers and heat exchangers.

What are the applications leveraging SS 304H tensile and yield strength?

Used in boilers, heat exchangers, and high-temperature piping, where high tensile and yield strength ensure durability under thermal stress. See sa240 gr 316ln.