304 vs 304H Stainless Steel Strength and Temperature Compari

304 vs 304H Stainless Steel: Strength and Temperature Comparison

At Gangsteel, we’re a top supplier of stainless steel plates, offering SA 240 GR 304 and SA 240 GR 304H that meet ASME SA 240 and ASTM A240 standards. 304 stainless steel (UNS S30400, AISI 304, EN 1.4301) is a versatile austenitic grade for general use, while 304H stainless steel (UNS S30409, AISI 304H, EN 1.4948) is a high-carbon version built for high-temperature strength.

 Both are non-magnetic and share a density of 8.00 g/cm³. This guide compares their strength and temperature performance for applications like plat stainless 304 and SA 240 GR 304 pipe. Contact us at admin@gangsteel.com or visit our ASME SA240 Stainless sheet for details.

Overview of 304 vs 304H Stainless Steel

304is a go-to choice for corrosion resistance in mild environments, like food processing or architecture. It’s easy to weld and form.

304His tailored for high-heat settings, with extra carbon for better creep resistance. It’s used in boilers and heat exchangers.

Both grades are austenitic, offering non-magnetic properties (SA 240 304 non magnetic). The key difference lies in carbon content, affecting strength and temperature limits. See sa240 gr 304 and sa240 gr 304h.

Chemical Composition Comparison

The carbon content sets 304 and 304H apart:

304H’s elevated carbon (0.04-0.10%) enhances creep resistance above 800°F (427°C) but may reduce weldability compared to 304 (≤0.08% C). For other elements, see our SS 304 data sheet.

Strength Comparison

Strength properties for annealed plates (8-75 mm thick) show slight differences:

• Room Temperature: Both have identical tensile (515 MPa) and yield strength (205 MPa), supporting applications like plat SS 304 3mm.
• High Temperature: 304H shines with better creep resistance. At 1000°F (538°C), 304H has an allowable stress of 25.5 ksi vs. 18.6 ksi for 304, per ASME BPVC Section II, Part D.

304His stronger in sustained high-heat conditions, making it ideal for load-bearing structures. See sa240 gr 304l for low-carbon options.

Temperature Performance Comparison

Temperature limits define their applications:

• 304:
  • Continuous: Up to ~1200°F (649°C).
  • Best for mild environments below 800°F (427°C).
  • Scaling starts at ~1200°F.
• 304H:
  • Continuous: Up to 1500°F (815°C).
  • Intermittent: Up to 1600°F (871°C).
  • Scaling onset at ~1200°F, but better creep resistance.

304H’s higher carbon (0.04-0.10%) extends its temperature range, making it suitable for high-heat applications like boilers. For chloride-heavy environments, explore sa240 gr 316l.

Corrosion Resistance

Both grades resist corrosion in:

• Mild acids, freshwater, and atmospheric conditions.
• General environments, outperforming SS204 vs SS 304.

304Hrisks sensitization (carbide precipitation) in weld zones due to higher carbon, requiring annealing. 304 is less prone but less heat-resistant. See sa240 gr 317l.

Weldability

• 304: Good with ER308 fillers; lower carbon reduces sensitization risk.
• 304H: Fair with ER308H fillers; higher carbon needs annealing to avoid corrosion loss.

For welds, consider sa240 gr 321.

Uses

• 304: Food processing, chemical tanks, architecture (plate 2 mm SUS 304).
• 304H: Boilers, heat exchangers, power generation (superheaters).

Pricing

As of October 19, 2025:

• 304: $1.55-$3.50/kg.
• 304H: $1.60-$3.50/kg.

Gangsteel offers $1.60/kg FOB for both (MOQ 1 ton). Contact admin@gangsteel.com or visit astm a 240 stainless plate.

Summary

304 stainless steelis ideal for general-purpose applications with good strength and corrosion resistance up to 1200°F. 304H stainless steel excels in high-temperature environments (up to 1500°F) with superior creep strength due to higher carbon, making it perfect for boilers and heat exchangers, though it requires careful welding. Gangsteel offers both at competitive prices ($1.60/kg FOB). Contact us for quotes.