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Steel Pipe Rolling Process

Pipe Rolling

We’ve got you covered when rolling or bending in your pipe projects. With a variety of bending options available, it’s important to make sure that your pipe parts work within the guidelines to ensure a successful.
Maybe you will like to check out our Pipe Rolling Machine page.

Roller rolling pipe, also known as pipe rolling or roll bending, is a metalworking process that involves using a set of rollers to bend and shape a metal pipe into a specific curve or configuration. The process typically uses three or four rollers, with two or three of them adjustable to create the desired bend. The metal pipe is fed through the rollers, and as it passes through, the rollers apply pressure and force to gradually bend the pipe. Roller rolling pipe is commonly used in various industries for applications like manufacturing, shipbuilding, construction, and more, to produce pipes with precise and controlled curvature for diverse structural and functional requirements.

3-roll Steel Pipe Rolling Process

The 3-roll pipe rolling process is a metalworking technique used to bend and shape metal pipes into specific curves, arcs, or configurations. It involves three rollers, two of which are positioned above the pipe and one below.
The process starts by placing the metal pipe between the bottom roller (back roller) and the adjustable top rollers. The top rollers are adjusted to the desired curvature or shape, and the pipe is gradually fed through the machine. As the pipe passes through the rollers, it is gradually bent to conform to the pre-set roller positions.
Incremental adjustments can be made during multiple passes to achieve the desired bend. The number of passes and the degree of adjustments depend on the complexity of the final shape.

W24S-600 Profile Bending Machine
PBH-700 Pipe Rolling Machine

Pipe and Tubing

Pipe and tubing is also known as HSS (hollow structural steel), just like square and rectangular tubing, since it is hollow.
Pipe rolling is a versatile technique employed in the fabrication of components for a wide range of applications. Roll bending, in particular, finds frequent use in the creation of large construction elements. This method typically involves the use of three rolls arranged in a pyramid formation, allowing for the precise formation of specific radii. It is also suitable for producing intricate shapes such as spirals and continuous coils.

Curved pipes, created through roll bending, have diverse applications in various sectors. They are utilized in the construction of bridges, stairs, and canopies. Additionally, these curved pipes find their place in machines used within the agricultural and construction industries. What’s notable is that pipes can be bent to achieve a consistent radius or shaped with varying degrees of ovality as per the client’s requirements. Furthermore, pipes can be bent along two planes, and multi-roll bending methods can be employed to achieve complex profiles and geometries. Further reading: The difference between tube and pipe

Bends Φ168mm steel pipe in Malaysia.
rolling pipe bending machine
Hydraulic Tube Bending
W24S-180 Profile Bending Machine
PBH-360 Pipe Rolling Machine

CHS Steel Pipe

CHS MEANING ‘CIRCLE HOLLOW SECTIONS’: Of all the steel hollow sections, the circular hollow section came first. The CHS section is a common feature in a wide variety of structural steel operations and has a lot of construction and mechanical uses. The consistent and clean lines of steel CHS make this circular tube a very aesthetic choice in many building designs.
CHS steel is popular for the construction of handrails, balustrades, and scaffolding. Other purposes include sign poles, columns, fences, and architectural features such as bending steel staircases. CHS can be fine-controlled and internally scarfed. This allows the tube to be suitable for mandrel bending.

Pipe and tubing is also known as HSS (hollow structural steel), just like square and rectangular tubing, since it is hollow.

Principle of Rolling Pipe

The principle of roller rolling pipe involves the controlled application of force and bending moments to gradually shape a metal pipe. This process utilizes three or four rollers, with some adjustable, to achieve precise bends. The key principles are:

  • Roller Configuration: The rollers are strategically positioned, with some adjustable to create the desired pipe curvature.
  • Incremental Bending: The metal pipe is passed through the rollers multiple times, with gradual adjustments, ensuring a controlled and uniform bend.
  • Material Deformation: As the pipe passes through the rollers, it undergoes plastic deformation, taking on the shape defined by the roller positions.
  • Roller Alignment: Proper alignment of the rollers is crucial to achieve the desired bend without causing damage to the pipe.
rolling pipe bending machine
pipe rolling machine
pipe rolling machine
rolling pipe bender

How to Bend Pipe Into a Circle

  • Measure: Determine the radius and angle of the bend and mark the pipe accordingly.
  • Secure: Place the pipe into a pipe rolling machine, ensuring it’s centered and secure.
  • Start Bending: Turn on the machine and slowly feed the pipe through the rollers or bending heads.
  • Gradual Bending: Apply gentle and consistent pressure as the pipe moves through the machine.
  • Check Progress: Monitor the pipe’s shape as it bends, and make any necessary adjustments to achieve a complete circle.
  • Complete the Bend: Once the desired shape is achieved, stop the machine and remove the bent pipe.
  • Inspect: Check for imperfections or deformities, and make corrections if needed.
  • Use: Your pipe is now bent into a circle and ready for your specific application, such as a hoop, frame, or part of a structure.

10 Major Advantages of the Modern Pipe Rolling Process

PBH-700 Angle Roller
  • Precision and Consistency: Modern machines are equipped with digital controls, ensuring precise and consistent pipe bending, even for complex shapes.
  • Versatility: These machines can handle various materials, such as steel, stainless steel, aluminum, and copper, as well as different pipe diameters and wall thicknesses.
  • Efficiency: Modern machines are efficient and can complete the bending process in fewer passes.
  • Reduced Material Waste: The precision of modern machines minimizes material waste as there are fewer errors and corrections needed.
  • Safety Features: Advanced safety mechanisms, including emergency stop buttons and safety interlocks.
  • Cost-Effective: With improved efficiency, reduced material waste, and high precision.
  • Automation: Some modern machines can be automated, reducing the need for manual labor and improving overall production efficiency.
  • Wide Application Range: These machines are used in various industries, from construction to automotive, aerospace, and more, due to their versatility and precision.
  • Consistent Quality: Modern roller rolling ensures that the final product consistently meets quality and performance standards.
  • Customization: Digital controls allow for easy adjustment and customization of bending parameters.

Applications of pipe rolling

hydraulic tube bending
hydraulic pipe roll bending
  • Elbows for general industrial applications.
  • Serpentine for heat exchanger. Flat, cylindrical, conic, bent tube bundles, …
  • Elbow for pneumatique conveying
  • Railings, handrails, and tubular arched portal
  • Tubular safety barriers
  • Exhaust pipe elbow
  • Tubular handrail and base rail for balanced staircase.
  • Small-thickness pipe elbow
  • Industrial facilities (chemical, petrochemical, pharmaceutical, food, etc.)
  • Agricultural machinery and equipment
  • Railways, naval, military, nuclear, and energy sectors
  • Metallic construction
  • Metallic parts furniture manufacturer
  • Building ironwork
  • Automotive equipment and construction machinery
  • Manufacture of safety and protective equipment
  • Boiler manufacturer, heat production, cold production
  • Pneumatic conveying systems

Bend Radii in Pipe Rolling

Understanding Bend Radii

When discussing bend radii in pipe rolling, we refer to the radius measured to the centerline of the square pipe. Different pipe rollers have various draw bend radius tooling, but a common guideline is the first rule of thumb: Standard draw bend radius is typically 2 times the pipe’s outside diameter (OD). For example, with a 20 mm OD pipe, the ideal bend radius is 40 mm, though it can be tighter, down to ½ x D, but this often incurs higher tooling and potential mandrel rolling costs.

Maximum and Minimum Bend Radii

The maximum draw bend radius isn’t determined by the pipe’s performance but by the tooling that can be accommodated on the rolling machine, potentially leading to tooling charges when deviating from the standard 2 x D. For larger radius bends, push or roll rolling becomes a viable solution, with the minimum roll rolling radius set at 7 x D. Going tighter than 7 x D is technically feasible but should be approached with caution, considering wall thickness and material properties.


It’s prudent to consult your pipe manipulator regarding available tooling for your chosen pipe diameter before designing your component. To allow flexibility in your designs, consider wide tolerances in your bend radii. For instance, if a 90-degree bend in a 20 mm pipe works for your design, label it as 50 mm +/- 10 mm.

Multiple Bend Radii

When multiple bends are needed, single-stack basic draw benders can accommodate one set of tooling at a time. Switching between bend radii can be complex and time-consuming. Designing with multiple radii should be necessary. When multiple radii are required, two-stack, three-stack, or multi-stack machines can be used. However, these options become less common as you move up the machine range. Pipes with bends close to each other but not in the same plane may require stack machines with cut-away tooling. Pipes with larger radii are suitable for push rolling but can be challenging with simple roll rolling.

Complex Bend Configurations

Certain pipe configurations, like loops or “knots,” can pose challenges for pipe manipulators and increase manufacturing costs. In such cases, joining sections may be necessary, adding welding costs. Avoiding intricate designs is often more cost-effective.

In summary, understanding bend radii, selecting appropriate rolling methods, and considering design constraints are essential in pipe rolling, ensuring cost-effective and manufacturable results for your project.

Further reading: The difference between tube and pipe