Overview
SS304L (AISI 304L Stainless Steel) is a low-carbon version of SS304 and belongs to the 300 Series Austenitic Stainless Steel Family. The “L” stands for Low Carbon, with a maximum carbon content of 0.03%, significantly reducing the risk of carbide precipitation during welding.
SS304L offers excellent corrosion resistance, outstanding weldability, good formability, and superior resistance to intergranular corrosion after welding. It is widely used in pressure vessels, pharmaceutical equipment, food processing systems, chemical processing equipment, storage tanks, piping systems, and welded structures.
Compared with SS304, SS304L provides better weldability and post-weld corrosion resistance, making it the preferred choice for heavily welded assemblies.
Material Specification
| Property | Value |
|---|---|
| Material Designation | AISI 304L |
| Material Family | Austenitic Stainless Steel |
| UNS Number | S30403 |
| EN Grade | 1.4307 |
| Density | 8.00 g/cm³ |
| Magnetic Property | Non-Magnetic (Annealed), Slightly Magnetic After Cold Working |
| Standard Forms | Sheet, Plate, Coil, Pipe, Tube, Bar, Wire |
Chemical Composition
| Element | Content (%) |
|---|---|
| Iron (Fe) | Balance |
| Chromium (Cr) | 18.0–20.0 |
| Nickel (Ni) | 8.0–12.0 |
| Carbon (C) | ≤0.03 |
| Manganese (Mn) | ≤2.00 |
| Silicon (Si) | ≤1.00 |
| Phosphorus (P) | ≤0.045 |
| Sulfur (S) | ≤0.030 |
| Nitrogen (N) | ≤0.10 |
Mechanical Properties
Annealed Condition
| Property | Value |
|---|---|
| Tensile Strength | ≥485 MPa |
| Yield Strength | ≥170 MPa |
| Elongation | ≥40% |
| Hardness | ≤92 HRB |
| Elastic Modulus | 193 GPa |
Typical Working Condition
| Property | Value |
|---|---|
| Tensile Strength | 485–620 MPa |
| Yield Strength | 170–310 MPa |
| Hardness | 70–95 HRB |
Physical Properties
| Property | Value |
|---|---|
| Density | 8.00 g/cm³ |
| Melting Point | 1400–1450°C |
| Thermal Conductivity | 16.2 W/m·K |
| Electrical Resistivity | 0.72 μΩ·m |
| Thermal Expansion Coefficient | 17.2 × 10⁻⁶/K |
| Specific Heat Capacity | 500 J/kg·K |
Corrosion Resistance
| Environment | Performance |
|---|---|
| Atmospheric Exposure | Excellent |
| Industrial Environment | Excellent |
| Food Processing Environment | Excellent |
| Pharmaceutical Environment | Excellent |
| Chemical Processing Environment | Good |
| Marine Environment | Good |
| Intergranular Corrosion Resistance | Excellent |
The low carbon content of SS304L minimizes chromium carbide precipitation during welding, providing superior corrosion resistance in welded zones.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ASTM / AISI (USA) | 304L |
| UNS | S30403 |
| EN (Europe) | 1.4307 |
| DIN (Germany) | X2CrNi18-9 |
| JIS (Japan) | SUS304L |
| GB/T (China) | 022Cr19Ni10 |
| ISO | X2CrNi18-9 |
Available Forms
| Product Type | Availability |
|---|---|
| Stainless Steel Sheet | Yes |
| Stainless Steel Plate | Yes |
| Stainless Steel Coil | Yes |
| Stainless Steel Pipe | Yes |
| Stainless Steel Tube | Yes |
| Stainless Steel Bar | Yes |
| Stainless Steel Wire | Yes |
| Pressure Vessel Plate | Yes |
Typical Applications
Food Processing Industry
- Food Processing Equipment
- Storage Tanks
- Conveying Systems
- Dairy Equipment
- Brewing Equipment
Pharmaceutical Industry
- Pharmaceutical Equipment
- Cleanroom Systems
- Sterile Storage Tanks
- Medical Fluid Systems
Chemical Processing Industry
- Chemical Storage Tanks
- Process Piping
- Heat Exchangers
- Pressure Vessels
Oil & Gas Industry
- Process Equipment
- Instrument Tubing
- Storage Systems
- Welded Structures
Architectural Industry
- Decorative Panels
- Structural Components
- Building Facades
- Handrails
Industrial Manufacturing
- Welded Assemblies
- Fabricated Components
- Tank Systems
- Industrial Machinery
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| Laser Cutting | Excellent |
| Waterjet Cutting | Excellent |
| CNC Machining | Good |
| Stamping | Excellent |
| Deep Drawing | Excellent |
| Bending | Excellent |
| TIG Welding | Outstanding |
| MIG Welding | Outstanding |
| Laser Welding | Excellent |
| Polishing | Excellent |
Advantages
Excellent Weldability
Ideal for heavy welded structures without requiring post-weld annealing.
Superior Intergranular Corrosion Resistance
Excellent resistance in welded zones.
Excellent Corrosion Resistance
Suitable for food, pharmaceutical, and industrial applications.
Outstanding Formability
Supports deep drawing, bending, and fabrication.
Hygienic Surface
Easy to clean and maintain.
Global Availability
One of the most commonly specified low-carbon stainless steels worldwide.
Limitations
Lower Strength Than SS304
Reduced carbon slightly lowers strength.
Lower Wear Resistance Than SS304
Not ideal for high-friction applications.
Chloride Resistance Lower Than SS316L
Not recommended for marine immersion.
Work Hardening During Machining
Requires proper tooling and cutting parameters.
Comparison with Other Stainless Steels
| Property | SS304L | SS304 | SS316L | SS316 | SS321 |
|---|---|---|---|---|---|
| Corrosion Resistance | Excellent | Excellent | Outstanding | Outstanding | Excellent |
| Weldability | Outstanding | Excellent | Outstanding | Excellent | Excellent |
| Intergranular Corrosion | Excellent | Good | Outstanding | Excellent | Excellent |
| Strength | Medium | Medium-High | Medium | Medium-High | Medium |
| Food Grade | Excellent | Excellent | Excellent | Excellent | Excellent |
| Cost | Medium | Medium | High | High | High |
Comparison with Common Engineering Metals
| Material | Density (g/cm³) | Corrosion Resistance | Weldability | Hygienic Applications |
|---|---|---|---|---|
| SS304L | 8.00 | Excellent | Outstanding | Excellent |
| SS304 | 8.00 | Excellent | Excellent | Excellent |
| SS316L | 8.00 | Outstanding | Outstanding | Excellent |
| Aluminum 6061 | 2.70 | Good | Good | Good |
| Carbon Steel A36 | 7.85 | Poor | Good | Poor |
| Titanium Grade 2 | 4.51 | Excellent | Excellent | Excellent |
Available Surface Finishes
Mill Finishes
- No.1 Finish
- 2B Finish
- BA (Bright Annealed)
- No.4 Finish
Decorative Finishes
- Mirror Polish (8K)
- Hairline Finish
- Satin Finish
- Vibration Finish
- Brushed Finish
- Sandblasted Finish
Functional Finishes
- Passivation
- Electropolishing
- Anti-Fingerprint Coating
- PVD Coating
Frequently Asked Questions (FAQ)
What is SS304L stainless steel?
SS304L is a low-carbon version of SS304 designed to provide superior weldability and improved resistance to intergranular corrosion.
What is SS304L used for?
Typical applications include:
- Storage Tanks
- Pressure Vessels
- Food Equipment
- Pharmaceutical Systems
- Chemical Processing Equipment
- Welded Structures
What is the difference between SS304 and SS304L?
| Property | SS304 | SS304L |
|---|---|---|
| Carbon Content | ≤0.08% | ≤0.03% |
| Weldability | Excellent | Better |
| Post-Weld Corrosion Resistance | Good | Excellent |
| Strength | Slightly Higher | Slightly Lower |
Is SS304L food grade?
Yes. SS304L is widely used in food processing and sanitary equipment.
Is SS304L better for welding?
Yes. SS304L is specifically designed for welded applications and minimizes carbide precipitation in heat-affected zones.
Can SS304L rust?
Like all stainless steels, under extreme chloride exposure or improper maintenance, corrosion may occur. However, SS304L provides excellent resistance in most environments.
Is SS304L suitable for pharmaceutical applications?
Yes. Its corrosion resistance, cleanliness, and weldability make it a common choice in pharmaceutical systems.
What is the difference between SS304L and SS316L?
| Property | SS304L | SS316L |
|---|---|---|
| Corrosion Resistance | Excellent | Outstanding |
| Chloride Resistance | Good | Excellent |
| Marine Applications | Limited | Recommended |
| Cost | Lower | Higher |
Why is SS304L commonly used in pressure vessels?
Because it combines:
- Excellent Weldability
- Good Strength
- Outstanding Corrosion Resistance
- Long-Term Reliability
making it ideal for tanks, piping, and pressure equipment.
Does GCNOV provide custom manufacturing services for SS304L?
Yes. GCNOV provides:
- CNC Machining
- Laser Cutting
- Sheet Metal Fabrication
- Tank Fabrication
- Pipe Welding
- TIG & MIG Welding
- Electropolishing
- Passivation
- Prototype Development
- Low-Volume Production
- Mass Production