Bending steel tube and pipes

Steel is one of the most used materials used in manufacturing pipes and tubes having varied shapes, sizes, and other variables. It not only offers an exceptional level of mechanical strength but is also corrosion resistant and stands tall against the test of time. Also, the hardness of steel is much higher when compared to other materials used in making the pipes and tubes. Owing to this, manufacturers have to pay special attention to the bending techniques used to create intricate bends and accurate curve angles and other measurements in the pipes and tubes made from varying degrees of steel. 

From choosing the right bending machine to deciding the procedural conditions from beforehand, there are a lot involved in the steel tube bending operation. Not acknowledging these variables can impact the production speed and also the quality of the end products. Considering this, we have curated a detailed guide about steel tube bending, including the best practices, factors to consider, and many more relevant facts. 

Steel tube bending: A brief introduction 

Firstly, let’s have a quick look at what the processes involved in the tube bending operations for steel-based products. It is a fabrication workflow that allows manufacturers to create bends in the workpiece as per the project requirements. The bending angle usually depends on the end application of the tube, along with the bend length and the position. For instance, HVAC pipes most require the creation of complete U-shaped bends continuously along the entire length. On the other hand, hand rails and other such elements do not require such extensive bends and intricate detailing.

Factors impacting the quality of bends in steel tubes and pipes 

Knowing the factors influencing the quality of the bends to be created in steel tubes and pipes will help you make a thorough and well-defined plan for the same. Furthermore, you can also prepare yourself to overcome the challenges and unforeseen events that might arise during the real-time production cycle. So, in this below section, we have briefly illustrated the variables you need to consider without fail. 

Material thickness

Firstly, the steel pipes and tubes that are used in manufacturing and fabrication industries vary in thickness of the material being used. Thicker the material wall, more force will be required to create the bend and vice versa. This is why you have to use mandrel when thicker pipes and tubes are used as the workpiece. It will counterbalance the force exerted on the outer walls by the pressure dies and prevent material distortion. On the contrary, for thin-walled pipes and tubes, it would be best to use empty bending where no mandrel is not used.

Steel grade

Another factor to consider is the steel grade used in making the pipes or tubes. Usually, the elastic coefficient of metal alloys like steel is greatly dependent on its grade. If the coefficient is too high, the springback action after the bending process is likely to happen, thereby damaging the workpiece or resulting in irregular-shaped bends. Similarly, a workpiece with negligible elasticity will be much harder to bend and that could damage the tooling set. This is why finding the right steel grade is essential for you to choose the apt bending technique and variables. 

Bend radius

When the bend radius is too small, the chances of structural deformation and stress concentration of the workpiece are quite high. Besides, under such cases, you can’t even leverage the mandrel to reduce the external force and prevent the deformation. Similarly, for an excessively large bend radius, too much force will be needed to create the bends, which might cause wrinkles and other forms of damage like thinning of the outer radii surface. Hence, determining the right measurement of the bend radius is crucial so that you can choose the best bending technique and the associated tooling set.

Bending procedure

There are several type of bending techniques which can be further implemented for steel pipes and tubes. For instance, empty bending is best suited for thin-walled steel pipes having lower internal resistance against external pressure. Similarly, if the workpiece tends to suffer from material distortion due to the external bending force, mandrel bending will be the ideal technique. On the contrary, when you do not require a tight bend radius, compression bending will be the best option since here the bending dye is kept stationary. 

Tooling and equipment

You also need to consider the tube bending toolset to be used for the procedure. For instance, if you want to proceed with mandrel bending, ensure the mandrel is in proper condition and can withstand the external force exerted. This would not only safeguard the workpiece but also ensure no damage comes to the mandrel. Choosing the right tool is extremely crucial if you accurately bend angles and prevent material distortion and deformation. 

Bending pressure and speed

The quality of the bends created will be greatly influenced by the pressure applied and the speed at which the dyes or the workpiece are moved. If you want to create tighter bends, keep the pressure consistent throughout and speed at a lower rate so that the material won’t get deformed by any means. Applying inconsistent pressure will create distortion in the workpiece material and can often lead to wrinkles, compression, and other forms of damage. 

Best  practices implemented for steel pipe and tube bending

  • Choosing the right equipment is essential to ensure the bend angles and radius created on the steel pipe or tube are accurate and precise. 
  • Quality control is also important because it allows professionals to create high-quality bent tubes without any hassle. 
  • You should implement appropriate inspection rules so that the workpiece can be thoroughly tested for structural integrity, bend angle and radius quality, and other such variables. 
  • User training about the instruments and bending procedures will help you avoid material damage and incorrect measurements.


In this article, we have shared all the details you would need to know to chalk out the plan for steel pipe and tube bending. Based on this, all you need to do is select the equipment units you will need for the fabrication technique and make a proper roadmap. Rest assured, tube bending is an essential manufacturing procedure that requires too much of accuracy and precision. 

Sign in to leave a comment
What material is used for tube bending?