Grade 316L
Austenitic stainless · 1.4404, AISI 316L
Low-carbon 316 for welded corrosive service.
Data sheet
| Designations | AISI 316L / SAE 30316L · UNS S31603 · EN 1.4404 (X2CrNiMo17-12-2) |
|---|---|
| Standards | EN 10088-2, ASTM A240 |
| Used for | pharma, marine, welded pipework |
Offered in
Metallurgy
Reference data for Type 316L Stainless Steel (Extra-Low Carbon Marine/Surgical), against ASTM A240, ASTM A276, EN 10088-2, ASTM F138 (biomedical).
Elemental composition
X2CrNiMo17-12-2 to 1.4404
- Chromium 17,00%16,00–18,00%
- Nickel 12,00%10,00–14,00%
- Molybdenum 2,50%2,00–3,00%
- Nitrogen 0,050%max 0,10%
- Carbon 0,020%max 0,030%
- Other additions 1,54%Mn, Si, P, S
- Iron 66,89%Balance
Proportions use the normalised midpoint of each specified range. The midpoint is a derived figure, not something the standard states: read the table for what is actually specified.
Performance profile
Comparative scores out of ten, for weighing one grade against another
These are relative ratings, not measured properties, and they carry no units. Use them to narrow a shortlist, then work from the specified values.
Composition as specified
| Element | Specified | Nominal |
|---|---|---|
| Iron Fe | Balance | 66,89% |
| Carbon C | max 0,030%cap | 0,020% |
| Chromium Cr | 16,00–18,00% | 17,00% |
| Nickel Ni | 10,00–14,00% | 12,00% |
| Molybdenum Mo | 2,00–3,00% | 2,50% |
| Manganese Mn | max 2,00%cap | 1,00% |
| Silicon Si | max 0,75%cap | 0,50% |
| Nitrogen N | max 0,10%cap | 0,050% |
| Phosphorus P | max 0,045%cap | 0,025% |
| Sulphur S | max 0,030%cap | 0,015% |
A cap is a ceiling, not a quantity: a heat may contain far less. The nominal column is the midpoint of each range, used for the chart's proportions only.
Mechanical and physical properties
| Property | Value |
|---|---|
| Tensile strength, ultimate | 485 MPa70,3 ksi |
| Yield strength, 0,2% offset | 170 MPa24,7 ksi |
| Elongation at break | 40% |
| Hardness | 160 HBW / 85 HRB |
| Modulus of elasticity | 193 GPa28 Mpsi |
| Density | 8 g/cm³0,29 lb/in³ |
| Thermal conductivity | 16,3 W/(m·K)113,1 BTU·in/(hr·ft²·°F) |
| Thermal expansion | 16 µm/(m·K)8,9 µin/(in·°F) |
Test condition not yet confirmed. These figures are typical values for the grade; the condition a bar was supplied in changes them materially, so ask us for the mill certificate before designing to a number.
Pitting resistance
PREN 26,05
Cr + 3,3 Mo + 16 N, across the full specified composition
- Freshwater0–20
- Brackish20–32
- Seawater32–40
- Extreme offshoreover 40
A standard states its elements as ranges, so a grade has a window rather than a single score. The bar is that window; the tick is the midpoint.
Corrosion and fabrication
Chloride and marine service
Exceptional resistance to localized pitting and crevice corrosion in seawater and saline solutions.
Acidic and chemical media
Resistant to sulfuric, acetic, formic, and tartaric acids, as well as acid salts.
Sensitisation and thermal behaviour
Virtually immune to intergranular corrosion after welding due to C <= 0.030%.
Welding
Outstanding; standard choice for heavy welded infrastructure without post-weld heat treatment.
Machining and cold forming
Machinability index 42% relative to AISI 1212. High ductility; easily deep-drawn, hydroformed, and cold forged.
Where it is used
- Pharmaceutical bioreactors, fermenters, and clean-in-place (CIP) piping
- Surgical orthopedic implants (ASTM F138 bone plates and screws)
- Marine propeller shafts and underwater instrumentation enclosures
- Offshore oil and gas subsea umbilical tubing
Medical · Pharmaceutical · Marine · Petrochemical · Offshore Energy
Performance scores in full
The same six scores the profile plots, as numbers.
| Property | 316L |
|---|---|
| Corrosion resistance | 9 / 10 |
| Weldability | 9.6 / 10 |
| High-temperature resistance | 7.4 / 10 |
| Tensile strength | 5.8 / 10 |
| Cold formability | 8.8 / 10 |
| Machinability | 4.5 / 10 |
This page is guidance for selecting a grade, not a specification. Design to the governing standard and the mill certificate for the heat you are supplied.
The specifications and data on this site are provided for general information only. Verify any real-world project with a qualified metallurgist before relying on these figures. We take no responsibility for the use and application of this information.