ss 304 material specification

What is SS 304 Material Specification?

SS 304 is specified under ASME SA 240 and ASTM A240 for chromium and chromium-nickel stainless steel plates, sheets, and strips used in pressure vessels and general applications. Equivalent designations include UNS S30400, 1.4301, and SUS304. The specification outlines chemical composition, mechanical properties, physical properties, and testing requirements to ensure suitability for applications like plat stainless 304, SA 240 GR 304 pipe, and architectural panels. Gangsteel’s sa 240 gr 304 plates meet these standards.

Chemical Composition of SS 304

The chemical composition of SS 304, as per ASME SA 240 and ASTM A240, ensures corrosion resistance and formability:

• Chromium (Cr): Forms a passive oxide layer for corrosion resistance.
• Nickel (Ni): Enhances ductility and SS 304 non magnetic properties.
• Carbon (C): Limited to ≤0.08% for weldability, though SS 304L (≤0.03%) is preferred for critical welds. See sa 240 gr 304l.

For detailed specs, refer to our SS 304 data sheet.

Mechanical Properties of SS 304

The mechanical properties of SS 304 for annealed plates (8-75 mm thick), as specified by ASME SA 240, support its use in structural and forming applications:

Cold-working can increase tensile strength (up to 900 MPa) but reduces ductility. For high-temperature applications, explore sa 240 gr 304h.

Physical Properties

• Density: 8.00 g/cm³ (SA 240 GR 304 density), ideal for lightweight designs (e.g., a 1m x 1m x 3mm plate weighs ~24 kg).
• Melting Point: ~1400-1450°C, suitable for processing.
• Thermal Conductivity: 16.2 W/m·K, moderate for heat transfer.
• Coefficient of Thermal Expansion: 17.2 × 10⁻⁶/K, stable across temperatures.
• Electrical Resistivity: 0.72 × 10⁻⁶ Ω·m, good for non-conductive applications.

These properties support applications like plat SS 304 3mm and plate 2 mm SUS 304.

Corrosion Resistance and Weldability

SS 304 offers excellent corrosion resistance in:

• Atmospheric conditions, freshwater, and mild acids (food-grade applications).
• General environments, outperforming SS204 vs SS 304 due to higher nickel content.

It’s less resistant to chloride-induced pitting compared to SS 316L (SA 240 GR 316L). Weldability is good with ER308 or ER308L fillers, but SS 304L is preferred for critical welds to avoid sensitization. For chloride-heavy environments, explore sa 240 gr 316l.

Applications of SS 304

SS 304’s specification supports its use in:

• Food Processing: Tanks, conveyors, and equipment (hygienic, non-tarnishing).
• Chemical Industry: Vessels and SA 240 GR 304 pipe for mild corrosives.
• Architecture: Structural and decorative panels like plat stainless 304.
• Automotive: Components requiring corrosion resistance and formability.

For harsher conditions, consider sa 240 gr 317l or sa 240 gr 321 for high-temperature stability.

Pricing and Availability

As of October 14, 2025, SS 304 (SA 240 GR 304) plate prices for 2B finish (3-6mm thick) range from $1.55-$3.50/kg globally, influenced by nickel prices (~$15,325/t). Gangsteel offers competitive pricing starting at $1.60/kg FOB (MOQ 1 ton) for standard sizes (e.g., 4’x8’, 5’x10’) and custom cuts like plate 2 mm SUS 304, with finishes like 2B, No.1, and polished. Our SS 304 plate price is 5-10% below market averages, and dual-certified SA 240 TP 304/304L plates are available.

Why Choose Gangsteel?

Gangsteel provides certified SS 304 (SA 240 GR 304) plates meeting ASME SA 240 specifications, with competitive SS 304 sheet price and custom sizes like plat stainless 304. Our 600+ ton inventory supports global delivery. For quotes or to learn what is SA 304, visit our astm a 240 stainless plate page or email admin@gangsteel.com.