stainless steel ss 304 and 304 specification

 

 

 

What is SS 304 and 304 Specification

SS 304and 304 refer to the same austenitic stainless steel grade, specified under ASME SA 240 and ASTM A240 for plates, sheets, and strips used in pressure vessels and general corrosive service.

Known as SA 240 GR 304, AISI 304, UNS S30400, or 1.4301, it features a density of 8.00 g/cm³ and non-magnetic properties in the annealed state. SS 304 is widely used in applications like plat stainless 304, plate 2 mm SUS 304, and SA 240 GR 304 pipe due to its excellent balance of strength, corrosion resistance, and formability. Gangsteel’s sa 240 gr 304 plates meet these rigorous standards.

 

Chemical Composition of SS 304 and 304

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

Element	Range (%)
Carbon (C)	0.00 - 0.08
Manganese (Mn)	0.00 - 2.00
Silicon (Si)	0.00 - 0.75
Phosphorus (P)	0.00 - 0.045
Sulfur (S)	0.00 - 0.030
Chromium (Cr)	18.00 - 20.00
Nickel (Ni)	8.00 - 10.50
Nitrogen (N)	0.00 - 0.10
Iron (Fe)	Balance

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

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

 

Mechanical Properties of SS 304 and 304

The mechanical properties of SS 304 for annealed plates (8-75 mm thick) support structural and forming applications:

Property	Value (Minimum)	Notes
Tensile Strength	515 MPa (74.7 ksi)	Strength before fracture
Yield Strength (0.2% Offset)	205 MPa (29.7 ksi)	Stress at plastic deformation onset
Elongation (A5, 50 mm)	40%	High ductility for forming
Hardness (Brinell)	≤ 201 HB	Supports machinability
Hardness (Rockwell B)	≤ 92 HRB	Alternative hardness metric

Cold-working (e.g., rolling) 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, 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 make SS 304 suitable for 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 is less resistant to chloride-induced pitting compared to SS 316L (SA 240 GR 316L), which contains molybdenum. Weldability is good with ER308 or ER308L fillers, but SS 304L is preferred for critical welds to minimize sensitization risks. For chloride-heavy environments, explore sa 240 gr 316l.

 

Applications of SS 304 and 304

SS 304 is used 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.
• Medical Devices: Non-magnetic instruments leveraging SA 240 304 non magnetic properties.

For harsher corrosive environments, consider sa 240 gr 317l. For high-temperature applications, explore sa 240 gr 321 for titanium-stabilized performance.

 

Pricing and Availability at Gangsteel

As of October 15, 2025, SS 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 for flexibility. For pricing details, contact admin@gangsteel.com.

 

Why Choose Gangsteel?

Gangsteel provides certified SS 304 (SA 240 GR 304) plates with consistent properties and competitive SS 304 plate price. Our 600+ ton inventory supports global delivery for applications from plat stainless 304 to heavy plates. For quotes or to learn more about SS 304 and 304 specifications, visit our astm a 240 stainless plate page or email admin@gangsteel.com.