Stainless steel and aluminum are two of the most popular metals used for manufacturing. Widely used for their versatility and corrosion resistance, aluminum and stainless steel are staples in the metals industry. To know when it is better to use aluminum vs stainless steel, we must compare factors like their compositions, mechanical properties, and cost.
Main Characteristics of Stainless-Steel vs Aluminum
Contains a minimum of 11% chromium
Is a ferrous alloy (contains iron)
High tensile strength
Stainless steel comes in a variety of grades. The grades are classified by a series number and assigned a numerical grade. The numbers classify the grades of steel based on their composition, physical properties, and applications. The most popular grades are 304 stainless steel and 316 stainless steel.
Both metals possess properties that are desirable for manufacturing a variety of products. However, the differences in their properties are a key factor when choosing which metal to use.
The Major Advantages of Each Metal
-High Tensile Strength
Aluminum vs Stainless Steel: Key Differences
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.
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.
Aluminum is a more costly than stainless steel if you look at price based on weight. But, if you look at price by volume, Aluminum is more cost effective because you get more product.
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.
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.
Composition of Major Stainless Steel Alloys
Composition of Major Aluminum Alloys
Environmental Impact, Recyclability
Stainless steel is known for its good recyclability. According to Napa Recycling, steel is the most recycled material in the world. It has distinct magnetic properties that make it an easy material to recover from the waste stream for recycling. In addition, the properties of steel remain unchanged no matter how many times the steel is recycled.
Even though steel is the most recycled material, aluminum is the most recyclable of all materials. As a matter of fact, discarded aluminum is more valuable than any other material in your recycling bin. Nearly 75% of all aluminum produced in the U.S. is still in use today because aluminum can be recycled over and over again in a true closed loop. To learn more about recycling aluminum, visit the Aluminum Association.
Different Applications of Aluminum vs Steel
Aluminum and steel are everywhere. If you look around at any given place, chances are you will see something containing one of these metals. Below are some common applications of stainless steel and aluminum.
Stainless steel is common in kitchen equipment due to its resistance to corrosion and heat
Food prep tables
You’ll find stainless steel in surgical tools and medical equipment due to its corrosion resistance
Stainless steel is also used in architecture because of its strength and durability, just in different applications
Monuments and sculptures
Stainless steel is also used in the automotive industry due to its strength and heat resistance
When comparing stainless steel vs aluminum, you see they both possess characteristics that make them popular materials for manufacturing. Knowing the differences between them helps you to know when to use aluminum vs stainless steel. For example, aluminum is used for electrical applications because it is conductive and lightweight while stainless steel is not. On the other hand, stainless steel is utilized for things like engines and processing equipment because of its strength, resistance to heat, and corrosion.
Sarah is a Digital Product Analyst at Kloeckner Metals. She graduated in May 2021 from Georgia College & State University with a Bachelor's Degree in Mass Communication with a focus in Strategic Communication and a minor in Rhetoric.