Stainless Steel
Stainless Steel 316L (UNS S31603) — Composition, Properties & Supply
316L (UNS S31603) is a low-carbon austenitic stainless with 2–3% molybdenum, offering better pitting and intergranular corrosion resistance than 304. Low carbon (≤0.03%) removes weld sensitisation risk, making it the general-purpose choice for chemical, food, pharmaceutical and marine service.
What is the chemical composition of Stainless Steel 316L?
| Element | Symbol | Content (wt%) |
|---|---|---|
| Fe | Fe | Balance |
| Cr | Cr | 16.0–18.0 |
| Ni | Ni | 10.0–14.0 |
| Mo | Mo | 2.00–3.00 |
| Mn | Mn | ≤ 2.00 |
| Si | Si | ≤ 0.75 |
| C | C | ≤ 0.030 |
| P | P | ≤ 0.045 |
| S | S | ≤ 0.030 |
Values are typical specification limits. Actual heat analysis is reported on the EN 10204 3.1 mill test certificate supplied with each shipment.
What are the mechanical properties of Stainless Steel 316L?
| Property | Value | Note |
|---|---|---|
| Tensile strength | ≥ 485 MPa | Room temperature |
| Yield strength (0.2% offset) | ≥ 170 MPa | Room temperature |
| Elongation | ≥ 40 % | Gauge length 50 mm / 4D |
| Hardness | ≤ 217 HB | Brinell / Rockwell |
What are the physical properties of Stainless Steel 316L?
| Property | Value |
|---|---|
| Density | 8.00 g/cm³ |
| Melting range | 1375–1400 °C |
| Thermal conductivity | 16.3 W/m·K |
| Elastic modulus | 193 GPa |
| Maximum service temperature | 800 °C |
What are the key characteristics of Stainless Steel 316L?
- 2–3% molybdenum gives better pitting resistance than 304
- Carbon ≤ 0.03% eliminates weld sensitisation
- Good cryogenic toughness and formability
- Far cheaper than nickel alloys or titanium
Where is Stainless Steel 316L used?
- Chemical piping, vessels and heat exchangers
- Food and pharmaceutical clean equipment
- Marine engineering and coastal architecture
- Medical instruments and devices
- Architectural cladding and decoration
Which standards and specifications cover Stainless Steel 316L?
What product forms are available?
Frequently asked questions
How long does 316L last in seawater?
316L performs acceptably in flowing seawater, but is prone to pitting and crevice corrosion in stagnant seawater, crevices or hot (>60 °C) chloride service. With PREN around 26 it is a mid-range pitting grade. For higher reliability move to superaustenitic (904L / 254SMO), duplex 2205 or Inconel 625.
What is the difference between 316 and 316L?
316L limits carbon to 0.03% versus 0.08% for 316, so chromium carbides do not precipitate at grain boundaries during welding or high-temperature service. It therefore resists intergranular corrosion and normally needs no post-weld anneal. Strength is slightly lower, which can be offset by nitrogen alloying (316LN). Prefer 316L for pressure equipment and welded structures.
Need Stainless Steel 316L bar, tube, plate or forgings?
Send the grade, dimensions, standard and quantity. We answer within 10 minutes on working days and quote within 24 hours, with EN 10204 3.1 certification.
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