Material
Thermal conductivity in a clad stack
Conductivity is quoted per metal and almost never applies to a finished pan as a single number. What a buyer actually cares about is how quickly heat spreads across the base, which depends on thickness and geometry as much as on the material.
At a glance
Specification at a glance
| Material | Conductivity (W/mK, indicative) | Role in the stack |
|---|---|---|
| Copper C11000 | about 380 | Fastest spreading, heaviest, most expensive |
| Aluminium 1050 | about 220 | The usual core, good compromise |
| Aluminium 3003 | about 160 | Core in 5-ply, better strength than 1050 |
| Carbon steel | about 50 | Not used in cookware clad |
| Stainless 430 | about 25 | Magnetic base, poor conductor |
| Stainless 304 | about 16 | Cooking face, poor conductor by design |
Why the stainless faces are thin
A pan face is a barrier, not a conductor. 304 conducts roughly sixteen watts per metre kelvin against two hundred for aluminium, so a thick face would fight the core. That is why faces are 0.4 to 0.5 mm and the core carries the thickness.
A stack is not an average
Heat crosses the layers in series, so the resistance adds. A thick low-conductivity face dominates the result more than its share of the thickness suggests. Quoting a single conductivity for the stack is technically possible and practically misleading.
What actually spreads heat
Lateral spreading, which is what a cook sees when the pan edge eventually heats, is driven by the core's conductivity multiplied by its thickness. Doubling the aluminium thickness does more for evenness than changing the alloy.
Numbers to ask for
Per-layer alloy and thickness, and the test method if a conductivity figure is claimed. A supplier who answers with one number for the pan either measured a specific sample under a stated method or is rounding a marketing claim.
Questions
Common questions
Is copper better than aluminium?
It conducts faster, about 380 against 220. It is also heavier and far more expensive, which is why copper sits at the top of a range.
Does a thicker base heat faster?
It heats more slowly and spreads more evenly. Faster heating comes from the hob, not the base.
What does 3003 add in 5-ply?
Strength in the core with better conductivity than stainless, which lets the build hold shape with slightly less total weight.
Can you quote a conductivity for the finished pan?
Not as a single meaningful number. Per-layer values and thicknesses describe the build honestly.
Does the pattern affect heat?
Negligibly. Surface texture affects appearance and release, not conduction.