304 vs 304L vs 304H Stainless Steel Detailed Analysis

304 vs 304L vs 304H Stainless Steel: Detailed Analysis

At Gangsteel, a leading manufacturer and exporter of stainless steel products, we supply premium SA 240 GR 304, SA 240 GR 304L, and SA 240 GR 304H plates compliant with ASME SA 240 and ASTM A240 standards. These grades—304 (UNS S30400), 304L (UNS S30403), and 304H (UNS S30409)—are austenitic stainless steels with distinct properties driven by carbon content variations. This guide provides a detailed analysis of 304 vs 304L vs 304H stainless steel, focusing on chemical composition, mechanical properties, corrosion resistance, weldability, and applications like plat stainless 304 and SA 240 GR 304 pipe. Contact admin@gangsteel.com or explore our ASME SA240 Stainless sheet offerings.

Overview of 304, 304L, and 304H Stainless Steel

304is a versatile grade for general-purpose applications, offering good corrosion resistance and formability.

304Lis a low-carbon variant, optimized for weldability and corrosion resistance in mild environments.

304His a high-carbon variant, designed for high-temperature strength and creep resistance up to 1500°F (815°C).

All three are non-magnetic in the annealed state (SA 240 304 non magnetic) with a density of 8.00 g/cm³.

Chemical Composition Comparison

The carbon content is the primary differentiator, impacting strength and weldability.

Carbon Analysis:

• 304L: Ultra-low carbon (≤0.03%) prevents sensitization, ideal for welded structures.
• 304H: High carbon (0.04-0.10%) enhances creep strength at high temperatures.
• 304: Balanced carbon (≤0.08%) for general-purpose applications.

For details, see our SS 304 data sheet.

Mechanical Properties Comparison

Mechanical properties vary due to carbon content, affecting strength and temperature performance.

Strength Analysis:

• Tensile Strength: 304 and 304H (515 MPa) outperform 304L (485 MPa), especially at high temperatures (304H: 25.5 ksi at 1000°F vs. 14.9 ksi for 304L).
• Yield Strength: 304 and 304H (205 MPa) provide better deformation resistance than 304L (170 MPa).
• Elongation/Hardness: All grades offer 40% elongation and ≤201 HB, supporting formability for plat SS 304 3mm.

See sa240 gr 304 and sa240 gr 304h.

Corrosion Resistance Comparison

All three grades resist corrosion in mild acids and atmospheric conditions, outperforming SS204 vs SS 304.

Differences:

• 304L: Low carbon minimizes sensitization, preserving weld zone corrosion resistance.
• 304H: Higher carbon risks sensitization in welds (797°F-1580°F), requiring annealing.
• 304: Balanced carbon; moderate sensitization risk.

For chloride resistance, see sa240 gr 316l.

Weldability Comparison

• 304L: Excellent with ER308L fillers; low carbon avoids sensitization.
• 304: Good with ER308 fillers; moderate sensitization risk.
• 304H: Fair with ER308H fillers; needs annealing to prevent corrosion loss.

For welds, consider sa240 gr 321.

Temperature Performance

• 304: Continuous up to ~1200°F (649°C); general use below 800°F.
• 304L: Continuous up to ~800°F (427°C); welding-focused.
• 304H: Continuous up to 1500°F (815°C); intermittent up to 1600°F (871°C).

304Hexcels in high-heat environments like boilers. See sa240 gr 304l.

Applications

• 304: Food processing, architecture, chemical equipment.
• 304L: Welded tanks, piping, medical devices.
• 304H: Boilers, heat exchangers, power generation.

For cost-effective options, see sa240 gr 201.

Cost Comparison

As of October 19, 2025:

• 304: $1.55-$3.50/kg.
• 304L: $1.50-$3.45/kg.
• 304H: $1.60-$3.50/kg.

Gangsteel offers $1.50-$1.60/kg FOB (MOQ 1 ton). Contact admin@gangsteel.com or visit astm a 240 stainless plate.

Summary

304is versatile for general use, 304L excels in weldability for mild environments, and 304H offers superior high-temperature strength (515 MPa, 205 MPa yield) due to higher carbon. All share excellent corrosion resistance and formability, but 304H is best for heat-intensive applications like boilers, while 304L suits welded structures.