Difference Between Aluminum And Stainless Steel Pipe And Tube

Metal pipe and tubing are everywhere in automotive, aerospace, industrial, architectural, research, and medical applications. The most common elements are aluminum and stainless steel pipe and tube materials, and each has attributes that make it the right choice for a given industry. Once you’ve determined whether you need piping or tubing, next you’ll want to choose the best metal for your application.

Choosing the Right Metal

When you’re choosing a tubing material, the choices might seem overwhelming; both aluminum and stainless steel pipe and tube come in a variety of alloys and tempers, each with its own physical and mechanical properties. Each metal has general properties that are true for all its alloys.

Mechanical Properties

One factor to take into consideration is the mechanical properties that are required for your application. In situations where strength is more important, you may choose stainless steel for its good strength-to-weight ratio and ability to gain significant strength from cold working. If you are focused on keeping components lightweight, aluminum may better suit your application. An aluminum part weighs one-third less than a stainless steel part of the same dimensions.

Corrosion Resistance

Another factor to consider is the corrosion resistance or heat resistance of metal tubing. In general, both stainless steel and aluminum offer corrosion protection, and the amount will vary depending upon the alloy chosen. The passivating oxide films that form on the surfaces of both metals help keep the metals from corroding.

Heat Resistance

One downside of passivation is that the oxide layer can inhibit electrical conduction. Consequently, stainless steels are not known for good electrical conductivity. Aluminum’s high conductivity, along with thermal conductivity three times greater than that of steel, has led to its use in power transmission lines. If moving electricity or heat is important in your application, aluminum may be the better option.

Regardless of whether your tube is intentionally conducting heat, you’ll want to ensure it can handle the temperature of its operating environment. Stainless steels with high concentrations of chromium and nickel retain strength at high temperatures. On the opposite end of the spectrum, aluminum’s tensile strength increases as temperature drops and stays tougher at cold temperatures than many steels.