ASTM A240 316L Stainless Steel Plate | UNS S31603
We supply ASTM A240 316L stainless steel plates for pressure vessels, chemical processing equipment, tanks, heat exchangers and general industrial fabrication.
316L / UNS S31603 / EN 1.4404 is a low-carbon, molybdenum-bearing austenitic stainless steel. Compared with 304L, the addition of molybdenum provides improved resistance to pitting and crevice corrosion, particularly in many chloride-containing environments.
Hot-rolled and cold-rolled plates are available in standard and customized dimensions with EN 10204 3.1 material certification and project-specific inspection.
ASTM A240 316L Stainless Steel Plate
ASTM A240 / A240M covers chromium and chromium-nickel stainless steel plate, sheet and strip for pressure vessels and general applications.
| Product | Typical Supply |
|---|---|
| Standard | ASTM A240 / A240M |
| Grade | 316 / 316L |
| UNS | S31600 / S31603 |
| EN / W.Nr. | 1.4401 / 1.4404 |
| Product | Plate / Sheet |
| Thickness | 2–60 mm |
| Width | Up to 2000 mm / Customized |
| Length | Up to 6000 mm / Customized |
| Condition | Hot Rolled / Cold Rolled |
| Surface | No.1 / 2B / 2D / No.4 / Special Finish |
| Certification | EN 10204 3.1 MTC available |
Special thicknesses, widths and cut-to-size plates can be supplied according to project specifications.
What Is 316L Stainless Steel?
316L is the low-carbon version of Type 316 stainless steel, containing chromium, nickel and approximately 2–3% molybdenum.
The molybdenum addition improves resistance to localized corrosion compared with conventional 304/304L stainless steel.
The low carbon content of 0.030% maximum helps reduce susceptibility to sensitization and intergranular corrosion during welding and other thermal fabrication processes.
Key characteristics include:
- Good resistance to pitting and crevice corrosion
- Better chloride resistance than 304L
- Excellent weldability
- Good formability
- Low-carbon chemistry
- Good general corrosion resistance
- Suitable for pressure-vessel and process-equipment fabrication
ASTM A240 316L Chemical Composition
| Element | 316L / UNS S31603 |
|---|---|
| Carbon (C) | 0.030% max |
| Manganese (Mn) | 2.00% max |
| Silicon (Si) | 0.75% max |
| Phosphorus (P) | 0.045% max |
| Sulfur (S) | 0.030% max |
| Chromium (Cr) | 16.0–18.0% |
| Nickel (Ni) | 10.0–14.0% |
| Molybdenum (Mo) | 2.0–3.0% |
| Nitrogen (N) | 0.10% max |
Final material acceptance should follow the specified ASTM A240/A240M edition and purchase specification.
ASTM A240 316L Mechanical Properties
Typical minimum room-temperature requirements for annealed 316L plate are:
| Property | 316L Requirement |
|---|---|
| Tensile Strength | 485 MPa / 70 ksi min |
| Yield Strength | 170 MPa / 25 ksi min |
| Elongation | 40% min |
| Hardness | 95 HRB max |
Actual values are reported on the Material Test Certificate supplied with each heat or production lot.
316 vs 316L Stainless Steel Plate
The main difference between 316 and 316L is carbon content.
| Item | 316 | 316L |
|---|---|---|
| UNS | S31600 | S31603 |
| Carbon, max. | 0.08% | 0.030% |
| Chromium | 16–18% | 16–18% |
| Nickel | 10–14% | 10–14% |
| Molybdenum | 2–3% | 2–3% |
| Tensile Strength, min. | 515 MPa | 485 MPa |
| Yield Strength, min. | 205 MPa | 170 MPa |
| Welded Fabrication | Good | Often preferred |
316L is widely selected for welded vessels and fabricated equipment because its lower carbon content reduces the risk of sensitization after welding.
Corrosion Resistance of 316L Plate
The 2–3% molybdenum content gives 316L better resistance to chloride-induced pitting than 304/304L.
Typical environments include:
- Chemical process fluids
- Food and pharmaceutical processing
- Coastal and marine atmospheres
- Water-treatment equipment
- Industrial process equipment
However, 316L should not automatically be considered suitable for continuous seawater immersion. Severe chloride environments may require duplex stainless steel, 6Mo grades or other higher-alloy materials depending on temperature, chloride concentration and design conditions.
Surface Finish & Delivery Condition
ASTM A240 316L plate can be supplied in different surface conditions:
- No.1 – Hot rolled, heat treated and pickled; commonly used for industrial plate.
- 2B – Smooth cold-rolled finish for general fabrication.
- 2D – Cold-rolled matte finish.
- No.4 – Brushed finish for equipment requiring improved appearance.
- BA / HL / Polished – Available for special applications.
For pressure vessels and industrial fabrication, No.1 hot-rolled plate is one of the most commonly specified conditions.
ASTM A240 vs ASTM A480
ASTM A240/A240M is the material specification defining requirements for stainless steel plate, sheet and strip.
ASTM A480/A480M provides general requirements for flat-rolled stainless steel products, including dimensional tolerances and other manufacturing and inspection requirements.
Thickness, width, length and flatness tolerances for ASTM A240 plate should therefore be evaluated according to the applicable ASTM A480/A480M requirements and purchase specification rather than using one universal tolerance value.
Applications of ASTM A240 316L Plate
316L stainless steel plates are widely used for:
- Pressure vessels
- Chemical process tanks
- Heat exchangers
- Reactor vessels
- Food-processing equipment
- Pharmaceutical equipment
- Water-treatment systems
- Pulp and paper equipment
- Petrochemical equipment
- Storage tanks
- Industrial fabricated components
Inspection & Certification
ASTM A240 316L plates can be supplied with:
- EN 10204 3.1 Material Test Certificate
- Chemical composition analysis
- Mechanical property testing
- Dimensional inspection
- Surface inspection
- PMI testing when specified
- Intergranular corrosion testing when required
- UT inspection for plate when specified
- Third-party inspection
NACE MR0175 / ISO 15156 compliance can also be evaluated when required by the project specification and applicable service conditions.
Frequently Asked Questions
What is ASTM A240 316L stainless steel plate?
ASTM A240 316L plate is a low-carbon molybdenum-bearing austenitic stainless steel plate with UNS designation S31603, commonly used for pressure vessels and corrosion-resistant industrial equipment.
What is the difference between 316 and 316L plate?
The main difference is carbon content. 316L contains a maximum of 0.030% carbon, making it particularly suitable for many welded fabrications where resistance to sensitization is important.
Is 316L stainless steel suitable for seawater?
316L provides better chloride resistance than 304L and is widely used in marine and coastal environments. For continuous seawater immersion or severe chloride exposure, higher-alloy or duplex stainless steels may be more appropriate.
What is the difference between ASTM A240 and ASTM A480?
ASTM A240 defines the stainless steel material requirements, while ASTM A480 provides general requirements and dimensional tolerance provisions for flat-rolled stainless steel products.
Related Stainless Steel Products
- ASTM A240 304/304L Stainless Steel Plate – General-purpose austenitic stainless steel plate.
- ASTM A240 317L Stainless Steel Plate – Higher-Mo stainless steel for increased corrosion resistance.
- ASTM A240 321 Stainless Steel Plate – Titanium-stabilized stainless steel for elevated-temperature service.
- ASTM A240 347 Stainless Steel Plate – Niobium-stabilized stainless steel plate.
- ASTM A240 904L Stainless Steel Plate – High-alloy stainless steel for severe corrosive environments.
- ASTM A240 S32205 Duplex Stainless Steel Plate – Higher-strength duplex plate with improved chloride resistance.
- ASTM A312 TP316L Stainless Steel Pipe – UNS S31603 process piping.
- ASTM A182 F316L Flanges – Forged stainless steel flanges for pressure piping.
ASTM A240 316L Plate Supplier
We supply ASTM A240 316L / UNS S31603 stainless steel plates in standard and customized dimensions for international industrial projects.
For quotation, please provide the grade, thickness, width, length, quantity, surface finish and required inspection documentation.
Order Example:
ASTM A240/A240M Type 316L Stainless Steel Plate, 16 × 1500 × 6000 mm, Qty. 10 pcs, No.1 Finish, EN 10204 3.1.
