Stainless steel is heavier and stronger than aluminum. In fact, aluminum is around 1/3 the weight of steel. Even though stainless steel is stronger, aluminum has a much better strength-to-weight ratio than stainless steel.
Conductivity
Steel is a poor conductor of electricity due to its dense protective oxide layer. On the other hand, aluminum is a very good electrical and thermal conductor.
Cost
Aluminum is more costly than stainless steel if you look at the price based on weight. But, if you look at price by volume, Aluminum is more cost-effective because you get more product.
Heat Resistance
When comparing stainless steel vs aluminum, stainless steel has much better resistance to heat with a melting point of 2500 ℉, while aluminum becomes very soft around 400 ℉ with a melting point of 1220 ℉. However, aluminum has the advantage over steel in cold temperatures. As the temperature decreases, the tensile strength of aluminum increases, while steel becomes brittle in low temperatures.
Corrosion Resistance
Aluminum does not rust; however, it does corrode when exposed to salt. Stainless steel is highly corrosion-resistant and does not easily rust. In addition, stainless steel is non-porous which gives it more resistance to corrosion.
