How Does A Press Brake Work?

Contact Us
We have over 20 years in manufacturing hydraulic press brake, shear and fiber laser cutting machine. Get an instant quote for your sheet metal fabrication projects now!
Get FREE Quote

What Is A Press Brake?

Press brake is a machine used for metal bending and forming. Press brakes drive the punches and die through different driven sources.

Thus, the dies can bend the sheet metal repeatedly many times to form profiles. Materials of different thicknesses and lengths require different bending forces.

Bending force is the tonnage exerted by the press brake. Press brakes produce tonnage in different ways.

The hydraulic press brake is suitable for bending with large tonnage. Driven sources are generally divided into mechanical, hydraulic, electric, and pneumatic types.

The name of the press brake is named after the driving method. The pneumatic bending machine drives the ram through air pressure.

The servo-electric press brake drives the ram to move through the servo motor. Servo electric press brake has very high precision and speed.

How does A Press Brake Work?

Modern press brakes can be mainly divided into mechanical, and hydraulic press brakes.

At present, the press brake has developed into the advanced CNC hydraulic press brake.

It can handle all kinds of complex and mass workpiece-forming tasks.

The mechanical press brake drives the flywheel through the motor. The staff operates the clutch drive fly control flywheel.

Thus, the crank drives the movement of other parts. The operation of the mechanical press brake is relatively simple.

The mechanical press brake can handle large tonnage bending.

The hydraulic press brake is driven by the synchronous movement of the hydraulic cylinder.

There is a hydraulic cylinder on each side of the uprights. The hydraulic cylinder is connected with the ram through the piston rod.

The movement of the hydraulic cylinder drives the ram up and down. The movement modes of the hydraulic press brake are divided into up-moving and down-moving.

The back gauges accurately position the workpiece through the movement of different axes. The hydraulic press brake has the advantages of high speed and high precision.

The disadvantage is that the tonnage of bending is limited.

The CNC press brake is a hydraulic press brake equipped with a CNC control system.

The CNC control system controls the movement of each part. CNC control system has modular programming functions and high precision.

The operator can set parameters through the control system. For example, bending angle, plate thickness, flange length, cycle time, stress, etc.

The CNC press brake is also equipped with an automatic feeding system. The movement of the ram and the back gauge accurately controls the position of the workpiece.

Synchronous movement of the motor drive axes of the back gauge and the ball screws. The back gauge can accurately measure the length of the flange being formed.

Adjust the bending angle by adjusting the ram movement through the control system. There are basically three bending methods: air bending, bottom bending, and embossing bending.

The choice of bending method has a great relationship with the thickness of the plate.

Air bending is the most common bending method. During air bending, the workpiece is not in full contact with the bottom die.

Air bending can be carried out with a relatively small tonnage.

The method of bottom bending and coining can also be used as needed. During bending, the hydraulic cylinders drive the movement of the ram.

The ram drives the upper die to exert pressure on the lower die on the workbench. The sheet metal in the middle forms a specific angle through the extrusion of the die.

After repeated bending many times, the final profile is obtained.

The shape of the punches and dies and the movement of the ram determine the angle and shape of the metal plate.

CNC press brake has flexible numerical control and programming functions, which is very friendly to operators.

How to set up a press brake?

First of all, understand the drawing of the bending workpiece, which is a very critical step. Determine the material, length, and thickness of the workpiece.

Bending angle, bending radius, flange dimension, and tolerance of the workpiece.

Secondly, choose the appropriate bending method and die.

According to the relationship between bending radius and metal thickness, select the appropriate bending method.

For example, air bending, bottom bending, and coining. Select the punches and dies that match the material of the bending workpiece.

Thirdly, determine the tonnage according to the tonnage table.

You can consult the corresponding tonnage estimation of the manufacturer. If it is air bending, you can refer to the tonnage chart to determine the tonnage.

The tonnage of bottom bending is four to six times that of air bending. The tonnage of coining is eight to ten times that of air bending tonnage.

Fourth, install and adjust the toolings. Check whether the thickness of the toolings and the proportion of the upper and lower dies are normal.

Adjust the stroke of the ram, otherwise, the toolings cannot be used normally. Adjust the upper limit point of the toolings to reserve the stay position of the ram.

Measure the distance between the upper and lower dies and set an appropriate gap. The tightness of the die can be adjusted according to the bending angle.

When bending, adjust it with a pressure gauge to avoid damage to the toolings.

Fifth, perform the program procedure of the press brake. This requires the operator to be familiar with the functions of the CNC controller.

There are many functions of programming, which can improve work efficiency after familiarity.

It can also be programmed offline and used directly by technicians after programming. At this stage, the workpiece cannot be bent directly.

If a bending test is required, scrap plates can be used. The production can be carried out after the bending test has no problems.

If there is a problem with the bent workpiece, you can check the program. After checking and correcting the program, you can operate the press brake.

These steps can save costs and improve efficiency.


There are many kinds of press brakes, such as mechanical press brakes, CNC press brakes, hydraulic press brakes, etc.

No matter how advanced the technology of the press brake is, its basic working principle is similar.

The modern CNC press brake is more advanced than the previous press brake technology, and the bending accuracy and efficiency have been greatly improved.

ADH produces various CNC press brakes, NC press brakes and large press brakes. You can consult our product experts to learn more about our press brake or other machines.

Contact Us
Don't know which machine to choose? Please contact our sales experts to recommend the most suitable machine for your sheet metal product.
Ask An Expert
Privacy PolicyTerms
Copyright © 2022