Overview
SS316L (AISI 316L Stainless Steel) is a low-carbon version of SS316 and belongs to the 300 Series Austenitic Stainless Steel Family. The addition of molybdenum (Mo) combined with a maximum carbon content of 0.03% provides outstanding corrosion resistance, superior weldability, and exceptional resistance to intergranular corrosion.
SS316L is widely recognized as one of the most versatile corrosion-resistant stainless steels and is extensively used in marine engineering, pharmaceutical equipment, biotechnology systems, food processing, medical devices, semiconductor manufacturing, offshore platforms, and chemical processing plants.
Compared with SS316, SS316L offers improved weldability and enhanced corrosion resistance in welded structures. It is often the preferred choice for critical applications where long-term corrosion performance is essential.
Material Specification
| Property | Value |
|---|---|
| Material Designation | AISI 316L |
| Material Family | Austenitic Stainless Steel |
| UNS Number | S31603 |
| EN Grade | 1.4404 |
| 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) | 16.0–18.0 |
| Nickel (Ni) | 10.0–14.0 |
| Molybdenum (Mo) | 2.0–3.0 |
| 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 | ≤95 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 | 1375–1400°C |
| Thermal Conductivity | 16.3 W/m·K |
| Electrical Resistivity | 0.74 μΩ·m |
| Thermal Expansion Coefficient | 16.0 × 10⁻⁶/K |
| Specific Heat Capacity | 500 J/kg·K |
Corrosion Resistance
| Environment | Performance |
|---|---|
| Atmospheric Exposure | Outstanding |
| Industrial Environment | Outstanding |
| Marine Environment | Outstanding |
| Salt Spray Environment | Outstanding |
| Chloride Environment | Excellent |
| Chemical Processing Environment | Excellent |
| Intergranular Corrosion Resistance | Outstanding |
SS316L provides superior resistance to:
- Chloride Pitting Corrosion
- Crevice Corrosion
- Saltwater Exposure
- Organic Acids
- Sulfur Compounds
- Intergranular Corrosion after Welding
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ASTM / AISI (USA) | 316L |
| UNS | S31603 |
| EN (Europe) | 1.4404 |
| DIN (Germany) | X2CrNiMo17-12-2 |
| JIS (Japan) | SUS316L |
| GB/T (China) | 022Cr17Ni12Mo2 |
| ISO | X2CrNiMo17-12-2 |
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 |
| Sanitary Tubing | Yes |
Typical Applications
Marine Industry
- Offshore Platforms
- Boat Hardware
- Marine Fasteners
- Ship Components
- Desalination Equipment
Pharmaceutical Industry
- Biopharmaceutical Equipment
- Sterile Processing Systems
- Cleanroom Equipment
- Medical Fluid Systems
Medical Industry
- Surgical Instruments
- Implant Components
- Orthopedic Devices
- Medical Equipment
Food & Beverage Industry
- Food Processing Equipment
- Dairy Systems
- Brewing Equipment
- Beverage Production Lines
Chemical Processing Industry
- Storage Tanks
- Process Piping
- Heat Exchangers
- Reactors
- Pumps & Valves
Semiconductor Industry
- Ultra-Clean Process Equipment
- Gas Delivery Systems
- High Purity Components
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| Laser Cutting | Excellent |
| Waterjet Cutting | Excellent |
| CNC Machining | Good |
| Deep Drawing | Excellent |
| Stamping | Excellent |
| Bending | Excellent |
| TIG Welding | Outstanding |
| MIG Welding | Outstanding |
| Laser Welding | Excellent |
| Electropolishing | Outstanding |
Advantages
Superior Corrosion Resistance
One of the most corrosion-resistant stainless steels available.
Excellent Marine Performance
Ideal for seawater and coastal environments.
Outstanding Weldability
Low carbon content minimizes carbide precipitation.
Excellent Hygienic Properties
Widely used in pharmaceutical and food-grade applications.
Exceptional Intergranular Corrosion Resistance
Maintains corrosion resistance after welding.
Long Service Life
Provides outstanding durability in aggressive environments.
Limitations
Higher Cost Than SS304L
Molybdenum increases material cost.
Work Hardening During Machining
Requires optimized cutting tools and machining parameters.
Lower Strength Than Duplex Grades
Not suitable for some ultra-high-strength applications.
Not Intended for Extreme High-Temperature Service
SS309 and SS310 perform better above 900°C.
Comparison with Other Stainless Steels
| Property | SS316L | SS316 | SS304L | SS304 | Duplex 2205 |
|---|---|---|---|---|---|
| Corrosion Resistance | Outstanding | Outstanding | Excellent | Excellent | Outstanding |
| Chloride Resistance | Excellent | Excellent | Moderate | Moderate | Outstanding |
| Weldability | Outstanding | Excellent | Outstanding | Excellent | Good |
| Intergranular Corrosion | Outstanding | Excellent | Excellent | Good | Excellent |
| Marine Applications | Excellent | Excellent | Limited | Limited | Outstanding |
| Strength | Medium | Medium | Medium | Medium | High |
Comparison with Common Engineering Metals
| Material | Density (g/cm³) | Corrosion Resistance | Marine Use | Weldability |
|---|---|---|---|---|
| SS316L | 8.00 | Outstanding | Excellent | Outstanding |
| SS316 | 8.00 | Outstanding | Excellent | Excellent |
| SS304L | 8.00 | Excellent | Limited | Outstanding |
| Titanium Grade 2 | 4.51 | Outstanding | Outstanding | Excellent |
| Aluminum 5083 | 2.66 | Excellent | Excellent | Excellent |
| Duplex 2205 | 7.80 | Outstanding | Outstanding | Good |
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
- Etched Finish
Functional Finishes
- Passivation
- Electropolishing
- Anti-Fingerprint Coating
- PVD Coating
- Pharmaceutical Grade Surface Finish
Frequently Asked Questions (FAQ)
What is SS316L stainless steel?
SS316L is a low-carbon molybdenum-bearing stainless steel designed for superior corrosion resistance and outstanding weldability.
What is SS316L used for?
Typical applications include:
- Marine Equipment
- Pharmaceutical Systems
- Medical Devices
- Food Processing Equipment
- Offshore Structures
- Chemical Processing Plants
What is the difference between SS316 and SS316L?
| Property | SS316 | SS316L |
|---|---|---|
| Carbon Content | ≤0.08% | ≤0.03% |
| Weldability | Excellent | Better |
| Intergranular Corrosion Resistance | Excellent | Outstanding |
| Welded Structures | Good | Preferred |
Is SS316L food grade?
Yes. SS316L is widely used in food, beverage, pharmaceutical, and biotechnology industries.
Is SS316L marine grade stainless steel?
Yes. SS316L is one of the most commonly specified marine-grade stainless steels worldwide.
Can SS316L rust?
SS316L offers exceptional corrosion resistance, but contamination, poor maintenance, or extreme chemical exposure may still cause localized corrosion.
Is SS316L suitable for pharmaceutical equipment?
Yes. SS316L is considered the industry standard for pharmaceutical and biotechnology processing equipment.
Can SS316L be electropolished?
Yes. SS316L responds exceptionally well to electropolishing and is commonly used for ultra-clean applications.
Why is SS316L preferred for welded structures?
Because it combines:
- Low Carbon Content
- Excellent Weldability
- Outstanding Corrosion Resistance
- Superior Long-Term Reliability
making it ideal for tanks, piping, and process equipment.
Does GCNOV provide custom manufacturing services for SS316L?
Yes. GCNOV provides:
- CNC Machining
- Laser Cutting
- Sheet Metal Fabrication
- Tube Fabrication
- TIG & MIG Welding
- Electropolishing
- Passivation
- Mirror Polishing
- Pharmaceutical Equipment Fabrication
- Prototype Development
- Low-Volume Production
- Mass Production