What is Plate Bending/Rolling? Everything You Need to Know is here
Updated: Aug 7
Plate bending is the process of shaping a flat metal plate into a curve, a cylinder, or a cone by feeding it through a set of rollers. It is also called plate rolling, and on a fab floor the two terms mean the same job. The plate is bent cold, so it keeps its full strength, which is why it suits heavy work like tanks, towers, and pressure vessels.
You must have seen ships, rockets, oil tanks, windmills, and several other large structures around you or on trips. If you are as curious as I am, you may have always thought about how these large structures are made. For such large metal structures to be made in the desired shapes, metal Plate Bending/Rollings are installed at the workshops and factories.
Plate Bending/Rolling machine operators put the metal plates between the rollers in the machine and set the bending force, which results in bending the sheet in the desired manner. Therefore, if you are planning to enter the metal Plate Bending/Rolling industry, it is necessary to learn what it is, why it is performed and how one can perform Plate Bending/Rolling.
Let’s understand Plate Bending/Rolling in detail and also discuss how it is performed using different types of machines.
What is Metal Plate Bending/Rolling?
Metal Plate Bending/Rolling is a process of putting the metal plate into a Plate Bending/Rolling/rolling machine and passing it through the machine. Once the attributes such as the bending force and others are set, the desired shape can be achieved.
As you can see in the above image, the metal plate is between the top and bottom roller. Both rolls rotate at different RPMs and put force on the metal plate to bend/roll it. Yet, this is not the whole process. Let us tell you more about how a metal Plate Bending/Rolling/rolling machine works.
How Does a Metal Plate Bending/Rolling/Rolling Machine Work?
There are 4 crucial steps one must follow in order to achieve desired metal plate shape through a metal Plate Bending/Rolling/rolling machine.
Setting bending force according to the desired radius
Placing the metal plate on the table to maintain uniform bending/rolling
Pre-Pinching/Pre-Bending the tails of the metal plate
Passing the metal plate through the Plate Bending/Rolling/rolling machine
Step 1: Setting Bending Force on the Plate Bending/Rolling Machine
A bending operator will first assess the workload of the Plate Bending/Rolling/rolling machine. Once they are through the assessment, they decide on the bending force to be applied on the metal plate to bend/roll the machine at desired ID or OD (Inside Diameter or Outside Diameter).
A decision on ID or OD is necessary since that is the result.
Step 2: Placing the Metal Plate on the Table to Restrict Unwanted Movement
When the operator puts the metal plate on the table, it limits the movement of the plate in an unwanted direction. This is necessary since a moving metal plate would be mis-bent during the process.
Step 3: Pre-Pinching / Pre-Bending before Commencing the Bending Process
Pre-pinching or Pre-bending is the process of bending both the tails of the metal plate at the initial stage to achieve the desired radius at tails during the bending. It also helps the operator do minimal process post-bending.
Step 4: Bending the Workpiece through the Metal Plate Bending/Rolling Machine
Now that the metal plate is on the stand with pre-pinching or pre-bending successfully achieved, the operator can place the metal plate between the top roll and the bottom roll(s). The bending process is crucial, and having an experienced operator is helpful for the workshops since Plate Bending/Rolling/rolling machines are a major investment.
Types of Machines used for Performing Plate Bending/Rolling Operations
All around the world, several industries such as shipbuilding, metal fabrication, wind energy, earth moving, metal structures, rocket shell making, oil tanks, tubes and pipes, and thousands of others utilize metal Plate Bending/Rolling machines to make varying sizes of equipment and metal structures.
These are the types of Plate Bending/Rolling/rolling machines that these industries use for performing their Plate Bending/Rolling/rolling operations:
All above types of machines can be classified into two types based on their guideway type:
Linear Guideway Plate Bending/Rolling machine
Swing Guideway Plate Bending/Rolling machine
Different industries require different machines according to the workload they want the machine to handle. The choice of the machine also depends on the precision levels and majorly on the skillset of the operators.
In our own 40 years, we have seen plate bending shape shells for shipbuilding, pressure vessels, wind turbine towers, oil and gas tanks, silos, rocket casings, and large pipes, on plate from 10 mm up to 160 mm.
Types of Plate Bending: Rolls, Radius, and Cones
Plate bending covers a few different shapes, and the shape decides the machine and the method. Here are the ones you meet most on the floor.
Cylinders and shells. The most common job, rolling a flat plate into a round shell for a tank or a pipe. A three-roll or four-roll machine handles this, closing the radius in stages.
Cones. Rolling a cone means the large end travels faster than the small end, so the plate pivots around the cone point. It is slower and takes an experienced operator.
Multi-radius and curved sections. Some parts need more than one radius across the same plate, or a gentle arc rather than a full circle. The roll gap is set differently along the pass to get there.
Pre-bending the ends. Every job starts by pre-bending the flat leading and trailing edges, so the shell does not finish with straight, unbent ends. This step decides how clean the weld seam turns out.
For the full working principle and a step-by-step guide to rolling a plate, including pre-pinching, springback, and cone rolling, see our detailed guide on the 3-Roll Plate Bending Machine working principle.
Wrapping Up
The plate-bending industry is larger than we can imagine, and we hope this article has helped you with your questions regarding the same. If you are in the Plate Bending/Rolling industry or a manufacturer who requires a metal Plate Bending/Rolling machine at their workshop, stop thinking and contact Himalaya Machinery to inquire about matching your needs. We would love to help you with your needs and improve your experience of buying a plate-bending machine.
Plate Bending FAQs
What is plate bending?
Plate bending is shaping a flat metal plate into a curve, cylinder, or cone by feeding it through rollers. It is done cold, so the plate keeps its strength. It is also called plate rolling.
What is the difference between plate bending and plate rolling?
On a fab floor they are the same job, bending flat plate into a curved shape. Some people use rolling for full cylinders and bending for simple curves, but the process and the machine are the same.
What is pre-bending in plate bending?
Pre-bending, also called pre-pinching, is curving the flat front and back edges of the plate before the main pass. It removes the straight, unbent ends so the weld seam closes clean.
Which machine is used for plate bending?
A plate bending machine, also called a plate roll. The common types are three-roll and four-roll, with the four-roll giving easier pre-bending and faster setup on repeat work.
What thickness of plate can be bent?
It depends on the machine and the plate grade. Our K-Series machines bend from 10 mm up to 160 mm, in 2500 mm and 3000 mm widths, rated at 26 kg/mm2, about 255 N/mm2.
How do you roll a plate on a bending machine?
In short: pre-bend both edges, make a gentle first pass, then close the radius in stages while feeding the plate back and forth. For the full step-by-step, see our working principle and rolling process guide.
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