Grade 316
Austenitic stainless · 1.4401, AISI 316
Molybdenum-bearing grade for better pitting and chemical resistance.
Data sheet
| Designations | AISI 316 / SAE 30316 · UNS S31600 · EN 1.4401 (X5CrNiMo17-12-2) |
|---|---|
| Standards | EN 10088-2, EN 10088-3, ASTM A240, ASTM A276 |
| Used for | chemical plant, marine fittings, dairy |
Offered in
- Stainless steel sheet
- Stainless steel plate
- Stainless steel tread plate
- Stainless steel round bar
- Stainless steel flat bar
- Stainless steel square bar
- Stainless steel angle
- Stainless steel channel
- Stainless steel tube
- Stainless steel pipe
- Stainless steel fittings
- Stainless steel flanges
- Stainless steel hollow bar
- Stainless steel mesh
- Stainless steel perforated sheet
- Stainless steel hex bar
Metallurgy
Reference data for Type 316 Stainless Steel (Marine Grade), against ASTM A240, ASTM A276, EN 10088-2.
Elemental composition
X5CrNiMo17-12-2 to 1.4401
- 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 0,040%max 0,080%
- Other additions 1,54%Mn, Si, P, S
- Iron 66,87%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 | 66,87% |
| Carbon C | max 0,080%cap | 0,040% |
| 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 | 515 MPa74,7 ksi |
| Yield strength, 0,2% offset | 205 MPa29,7 ksi |
| Elongation at break | 40% |
| Hardness | 175 HBW / 88 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
High resistance to chlorides and pitting due to 2.0–3.0% Mo; withstands typical marine splash zones.
Acidic and chemical media
Substantially higher resistance to dilute sulfuric acid, phosphoric acid, and acetic acid solutions than 304.
Sensitisation and thermal behaviour
Susceptible to sensitization in weld HAZ if subjected to continuous service in 425°C–860°C range.
Welding
Very Good; standard fusion techniques applicable; filler metal typically AWS ER316 or ER316L.
Machining and cold forming
Machinability index 40% relative to AISI 1212. Very Good; slightly higher work-hardening rate than 304 due to Mo content.
Where it is used
- Marine deck fittings, rigging, and fasteners
- Chemical plant valve bodies and pump casings
- Petrochemical heat exchangers and distillation trays
- Industrial dyeing and textile processing machinery
Marine · Petrochemical · Chemical Processing · Textiles
Performance scores in full
The same six scores the profile plots, as numbers.
| Property | 316 |
|---|---|
| Corrosion resistance | 8.8 / 10 |
| Weldability | 8.8 / 10 |
| High-temperature resistance | 7.5 / 10 |
| Tensile strength | 6.2 / 10 |
| Cold formability | 8.5 / 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.