Grade matters
Ferritic grades often have higher conductivity than common austenitic grades.
Technical guide
Stainless Steel Thermal Conductivity Chart
Thermal conductivity varies by grade and temperature. Stainless steels generally conduct heat less readily than carbon steel, but calculations must use the exact alloy, temperature range and geometry.
Property symbolk or λ
SI unitW/(m·K)
Reference basisSelected values at 20 °C
Decision summary
Select conductivity by grade and temperature
A single room-temperature value is useful for screening, not for every heat-transfer or thermal-stress calculation.
Temperature matters
Conductivity changes as temperature rises; use temperature-dependent data for wide ranges.
Geometry controls heat flow
Area and path length matter alongside conductivity and temperature difference.
Interfaces add resistance
Contact condition, oxide, coatings, gaps and fouling can dominate an assembly.
Convection is separate
Surface heat-transfer coefficients are not material thermal conductivity.
Expansion also matters
Temperature gradients create distortion and stress according to expansion and restraint.
Reference table
Selected conductivity values at 20 °C
Values are from the cited worldstainless technical property table and are rounded as published for screening.
| Grade / EN number | Family | Thermal conductivity W/(m·K) | Design note |
|---|---|---|---|
| 304 / 1.4301 | Austenitic | 15 | Use temperature-dependent producer data for broad ranges. |
| 304L / 1.4307 | Austenitic | 15 | Similar room-temperature screening value to 304. |
| 316L / 1.4404 | Austenitic | 15 | Do not infer corrosion performance from conductivity. |
| 321 / 1.4541 | Austenitic | 15 | Heat treatment and service limits remain separate. |
| 430 / 1.4016 | Ferritic | 25 | Higher than common austenitic screening value. |
| 410S / 1.4000 | Ferritic | 30 | Confirm exact grade and temperature basis. |
| 2205 / 1.4462 | Duplex | 15 | Use grade datasheet for temperature-dependent design. |
These values are physical-property references, not acceptance limits. Producer data may show values at additional temperatures and with different rounding.
Working method
Estimate conduction without losing the assumptions
For steady one-dimensional conduction through a uniform section, heat rate Q equals k times area times temperature difference divided by path length.
Choose k
Use the grade-specific value at a representative temperature or integrate temperature-dependent data.
Define geometry
Use heat-flow area and path length in compatible SI units.
Apply boundary conditions
State hot and cold temperatures, contact resistance and whether steady state is justified.
Validate the model
Escalate multidimensional, transient, radiative or convective systems to a full thermal analysis.
Limits and escalation
Know when the simple conductivity model fails
Welds and layers differ
Filler, cladding, insulation, coatings and scale create a composite path.
Temperature may not be uniform
Large gradients make one room-temperature k value inadequate.
Contact resistance can dominate
Bolted, rough or oxidized interfaces may control heat flow.
Phase and condition matter
Exact composition, microstructure and temperature affect properties.
Interactive planning aid
Estimate one-dimensional heat flow
Select a grade and enter area, thickness and temperature difference. The result assumes steady conduction through a uniform flat section with no interface losses.
Frequently asked questions
Stainless steel thermal conductivity FAQ
The cited table lists about 15 W/(m·K) at 20 °C for 304-family flat-product data. Use temperature-dependent data for design across a wide range.
The cited 20 °C values are about 25 W/(m·K) for 430 and 15 W/(m·K) for 304.
No. Thermal conductivity and corrosion resistance are different properties controlled by different aspects of alloy and environment.
No. Heat-exchanger design also requires convection, fouling, flow, phase change, geometry, pressure drop and code requirements.
Method, sources and review
Traceable sources and review status
Industry-hosted 20 °C conductivity values by stainless grade.
Industry property overview and technical-table access.
Producer physical-property data for common austenitic and ferritic grades.
Producer information for duplex grades and physical-property datasheets.
Use grade- and temperature-specific producer data for final thermal design. The table and calculator are simplified planning references.
Thermal conductivity context
Use conductivity values with the temperature range and design condition.
Thermal conductivity varies with alloy, temperature, microstructure and product form. Confirm the operating range, heat-flow direction and the data basis before using a chart value.
- Operating range
- Material condition
- Data basis
Visual process context
Show the service setting and the thermal verification route.
Reserve one image for the heat-transfer environment and another for the material, test setup or design verification context.
Engineering and sourcing support
Request stainless with thermal inputs defined
Send grade, form, dimensions, temperature range, heat-flow duty, environment, fabrication, testing, quantity and destination.