Difference Between Aluminum And Stainless Steel

Aluminum and stainless steel are widely used for their versatility and corrosion resistance and are the main materials in the metals industry. To know when it is better to use aluminum versus stainless steel, we must compare factors such as their composition, mechanical properties, and cost.

Stainless steel:

Contains at least 11% chromium, is a ferroalloy (containing iron), usually magnetic, High tensile strength.

Stainless steel comes in a variety of grades. Grades are sorted by serial number and assigned a numerical grade. These numbers categorize the grade of steel based on its composition, physical properties and application. The most popular grades are 304 stainless steel and 316 stainless steel.

Aluminum:

non-magnetic, low density, Non-ferrous alloys (without iron).

Due to its low tensile strength, aluminum is often alloyed with other metals to give it many different superior properties. Some of the most common aluminum alloys are 3003 aluminum and 3004 aluminum.

Main difference:

Strength:

Stainless steel is heavier and stronger than aluminum. In fact, aluminum weighs about 1/3 that of steel. Although 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. Aluminum, on the other hand, is a very good conductor of electricity and heat.

Cost:

If you look at the price by weight, aluminum is more expensive than stainless steel. However, if you look at the price in terms of volume, aluminum is more cost-effective because you can get more product.

Heat resistance:

When comparing stainless steel to aluminum, stainless steel is much more heat resistant and has a melting point of 2500°F, while aluminum becomes very soft around 400°F and has a melting point of 1220°F. However, aluminum has advantages over steel at low temperatures. The tensile strength of aluminum increases with decreasing temperature, while steel becomes brittle at low temperatures.

Corrosion resistance:

Aluminum does not rust; however, it does corrode when exposed to salt. Stainless steel has strong corrosion resistance and is not easy to rust. In addition, stainless steel is non-porous, which makes it more resistant to corrosion.

Aluminum is common in the transportation industry, electrical industry, construction and household appliances.

Stainless steel is common in kitchen equipment, surgical tools and medical equipment, the automotive industry and construction.