Steel Pipe and Steel Tube are two different things, but there is a good chance that you may not be entirely sure what that difference actually is. A lot of people, even experts working within the field, are not aware of the exact differences between these two types of products. Bother cylindrical and hollow, so how can they be that different?

It turns out that looks can be confusing. Many confuse the real differences between these two types of steel product. Read the article below to find out what the differences between steel tube and steel pipe really are.


What is Steel Tubing? 

Steel tubing is used generally for structural purposes and the outer diameter has a very important exact number. Tubing size is determined by the outer diameter and the wall thickness. Tubing tends to be more expensive than pipe due to the tighter restrictions around it’s manufacturing tolerances.

While most steel tubing has a measured outer diameter and a stated outer diameter close to each other, copper tubing has a measured outer diameter that is roughy 1/8” larger than it’s stated outer diameter. It is differentiated by being called copper pipe. However, aluminium, steel and stainless steel tubing all conforms the rule that the outer diameters are very similar.


What is Steel Pipe?

Steel pipe is a tubular vessel used the construction of pipelines and piping systems. It traditionally transports gases or fluids. Steel Pipe has a ‘Nominal Pipe Size’ (NPS) and Schedule (or wall thickness). These standards are set by bodies such as the American National Standards Institute (ANSI), and shouldn’t be confused with other thread standards such as National Pipe Thread (NPT) or NPSC.

Nominal pipe sizes are manufactured based on standardised measurements from 1/8” to 12”. The reason why plumbers, engineers and other tradespeople mistake the NPS for the ID on smaller pipes is due to how they were originally defined. Standardised outer diameter was originally defined by a wall thickness that was near to the pipe ID.


So What Are The Differences Between Tubing And Pipe?

It is a very common question to ask the difference between pipe and tube. They may look similar, however they quite different in their structure and sizing standards. It is not often that they can be used interchangeably, so it is important to know the differences between the two.

Below are some of the qualities that differentiate steel tubing and steel pipe:

Shape – Steel pipes are always round in shape. However, Steel tubing can come in a variety of shapes, including rectangular or round.

Strength – Tube is far stronger than pipe as it used for structural purposes.

Metal Types – Steel tubing is available as hot-rolled or cold-rolled. Steel pipe is typically only produced using a hot rolling process. Both of these items can be galvanised, by applying a thin coat of zinc to improve the corrosion resistance of the steel.

Rigidity – Tube is typically a rigid structure. Pipes however can be more ductile and shaped to suit special conditions.

Size – Pipe tends to be available in larger sizes than tubing. Tubing typically encompasses a smaller size range.

Applications – Pipes rated for their pressure so as to accomodate the transfer of gases and fluids. Tubing is typically used for structural applications and is considered a form of structural steel.

Measurement – Pipes have a internal diameter (or nominal diameter) and a schedule (or wall thickness). This is due to the fact that the internal/nominal diameter is most important for piping where what is being transferred within the pipe is the most important consideration. Tube measuring however has a range of wall thickness measurements and is typically measure by the outside diameter.




Steel tubing and steel pipe may look similar, however they have two very different applications. You would not like to use steel tubing in a plumbing system, nor would you expect ti find steel pipe in any structural steel project.

Steel piping has been optimised for the transference of liquids and gases, whilst steel tubing has been prepared to be strong and good for supporting structures. Getting these two mixed up can be dire.

If you are interested in finding out more about steel pipe or tubing, you should contact your local steel pipesupplier or steel tubing supplier. They will have a large amount of resources outlining what type of steel is perfect for your project.