When you need to move heat, these are the best conductors in our library, ranked by thermal conductivity. Copper and aluminum lead by a wide margin.
| Material | Thermal conductivity (W/m-K) |
|---|---|
| Copper | 400 |
| Aluminum (6061) | 167 |
| Brass | 120 |
| Bronze | 60 |
| Gray Cast Iron | 55 |
| Carbon Steel | 50 |
| Titanium | 22 |
| Stainless Steel (304) | 16 |
Copper conducts heat about 25 times better than stainless steel, which is why heat sinks and cookware bases use copper and aluminum rather than steel.
FAQ
Does higher thermal conductivity always mean a better heat sink? Not entirely. Conductivity affects how quickly heat spreads through the material, but overall heat sink performance also depends on surface area, airflow, and how well the sink is thermally bonded to the heat source. A well-designed aluminum sink can outperform a poorly designed copper one.
See the Thermal Conductivity Chart and the Specific Heat Chart.
What thermal conductivity means
Thermal conductivity describes how well a material carries heat, and it is usually given in watts per meter kelvin. Copper and aluminum conduct heat very well, which is why they are used for heat sinks, cookware, and heat exchangers, while stainless steel and plastics conduct heat poorly and act more as insulators.
Choosing a material
Copper conducts better than aluminum, but it is heavier and more expensive, so aluminum is common when weight and cost matter. Low conductivity has effects in machining too, since materials such as stainless steel and titanium hold heat in the cutting zone instead of carrying it away. Thermal expansion and the interface between parts also affect how well heat actually moves in a real design.