Grade 310S
Austenitic stainless · AISI 310S / SAE 30310S, UNS S31008, EN 1.4845
Type 310S High-Temperature Oxidation-Resistant Stainless, austenitic stainless steel.
Data sheet
| Designations | AISI 310S / SAE 30310S · UNS S31008 · EN 1.4845 (X8CrNi25-21) |
|---|---|
| Standards | ASTM A240, ASTM A276, EN 10095 |
Metallurgy
Reference data for Type 310S High-Temperature Oxidation-Resistant Stainless, against ASTM A240, ASTM A276, EN 10095.
Elemental composition
X8CrNi25-21 to 1.4845
- Chromium 25,00%24,00–26,00%
- Nickel 20,50%19,00–22,00%
- Carbon 0,050%max 0,080%
- Other additions 1,99%Mn, Si, P, S
- Iron 52,46%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 | 52,46% |
| Carbon C | max 0,080%cap | 0,050% |
| Chromium Cr | 24,00–26,00% | 25,00% |
| Nickel Ni | 19,00–22,00% | 20,50% |
| Manganese Mn | max 2,00%cap | 1,20% |
| Silicon Si | max 1,50%cap | 0,75% |
| 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 | 520 MPa75,4 ksi |
| Yield strength, 0,2% offset | 205 MPa29,7 ksi |
| Elongation at break | 40% |
| Hardness | 170 HBW / 88 HRB |
| Modulus of elasticity | 200 GPa29 Mpsi |
| Density | 8 g/cm³0,29 lb/in³ |
| Thermal conductivity | 14,2 W/(m·K)98,5 BTU·in/(hr·ft²·°F) |
| Thermal expansion | 15,8 µm/(m·K)8,8 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 25
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
Good general corrosion resistance, but optimized for high-temperature service rather than aqueous halide immersion.
Acidic and chemical media
Resistant to high-temperature sulfur-bearing gases; high Cr and Ni provide outstanding resistance to molten cyanide and salts.
Sensitisation and thermal behaviour
Lower carbon variant (310S) minimizes carbide precipitation during cyclic thermal exposure up to 1150°C (2100°F).
Welding
Good; fully austenitic weld deposit is sensitive to hot cracking/microfissuring; low heat input and matching 310 filler required.
Machining and cold forming
Machinability index 35% relative to AISI 1212. Good; higher alloy content accelerates work hardening.
Where it is used
- Industrial furnace conveyor belts, rollers, and burner nozzles
- Radiant heating tubes and muffle furnaces
- Fluidized bed combustor components and coal gasifier internals
- Thermal recuperators and cryogenic vessels
Thermal Processing · Energy · Petrochemical · Aerospace
Performance scores in full
The same six scores the profile plots, as numbers.
| Property | 310S |
|---|---|
| Corrosion resistance | 8.5 / 10 |
| Weldability | 8 / 10 |
| High-temperature resistance | 10 / 10 |
| Tensile strength | 6.4 / 10 |
| Cold formability | 7.8 / 10 |
| Machinability | 3.8 / 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.