What is a Press Brake? (2023)

One of the benefits of many types of metals is the fact they are relatively ductile; ductility ensures that metals bend before they break. This ductility allows them to be formed to be a certain shape and size. This makes metals versatile, since oftentimes flat pieces of sheet metal must have their shape altered to be useful. Many pieces of forming equipment can be used to do this, but one of the most common is the press brake.

This article discusses what a press brake is, how it works, different types, applications and some additional considerations.

What do press brakes do?

A press brake is a piece of manufacturing equipment that is used to bend sheet metal. It is typically narrow and long so that large pieces of sheet metal can be bent by it. Press brakes perform these bends by clamping the sheet or plate between the movable punch and the stationary die. The bends are all predetermined, and the punch and die are designed for specific lengths and shapes. A metal may be bent several times by a press brake until the desired form has been achieved.

Why is it called a press brake?

Why is a press brake called a ‘press brake’ to begin with? In the 14th century a “brake” was defined as a tool for crushing and pounding; over time that term became synonymous with machine.

“Press” comes from the word “presse,” which was used as a noun meaning “to crush or to crowd”; the term evolved to mean a machine or tool that applies force by squeezing. In modern times, press is added to brake as a modifier to describe what actuates the machine, what tools are used to form the workpiece or what types of bends the machine produces.

How does the bending process work?

Bending sheet metal requires a large amount of force (measured by tonnage), and to achieve and deliver this force, the punch is lowered onto the sheet metal through several different methods. In application, there are various types of press brake technology, including:

• Hydraulic (i.e. CNC press brakes)
• Pneumatic
• Electric power
• Mechanical

The method of force application is often included in the name of a press brake (e.g., hydraulic press brake, servo electric press brake).

Press brakes also vary in the amount of force they can provide. On a press brake this is known as tonnage; it is a measure of tons of force that the press brake can deliver. As a rule of thumb, the higher the tonnage, the thicker metal that can be worked. Typically, hydraulic presses are used to achieve very high amounts of force, and pneumatic and servo electric presses provide lesser amounts of force.

The different types of press brakes also have different speeds and accuracies as well. A servo electric press brake will generally have the highest degree of accuracy. Pneumatic and servo electric press brakes save time as they are typically faster than hydraulic and mechanical brakes as well.

Additional considerations

Press brakes can make a variety of different bends on many different types of metals. When preparing to bend, it is important to consider the metal type being bent, the die, the punch, and the bending force.

Understanding the metal type is important because each metal has differing physical properties. For instance, a high carbon steel will generally be less bendable by a press brake than many aluminium alloys because of the differences in ductility and strength. Metals typically have a recommended minimum bend radius or distance that they can be bent to without being damaged.

The die and the punch used on the press brake both have a large impact on the bending results. They are a set designed in such a way that when the sheet metal is clamped between them it bends into the pre-determined shapes and angles. The die is a hollow material that the metal is placed on top of prior to bending. It is a very hard and strong substance that is near in form to the desired shape of the metal being bent.

The punch is a solid material that is lowered down onto the metal. Since the pressing action of the punch onto the metal and the die are what causes the metal to bend, both shapes must be accurately suited to the bending job.

The correct metal shape following a press brake operation is dependant on the size and shape of the punches and dies. Dies and punches are typically designed in such a way that they can be interchanged easily to accommodate a wide array of jobs.

Common press brake applications

Since press brake machines can be fitted with a wide range of punches and dies, they can be used for almost any sheet or plate metal shaping applications. The most common are:

• Automotive panels
• Airframes
• Metal artwork
• Furniture or appliances
• Metal containers
• Many other sheet metal forming applications

Almost any sheet or plate metal bending application can be accomplished using a press brake. Press brakes are most often used to produce multiple pieces of the same workpiece for further processing.

Bending metal at Metal Supermarkets

Working on a project and need to bend and shape your metal into different forms without purchasing the necessary machinery? Let us take away the guess work and do it for you!

At Metal Supermarkets we provide bending and press brake services at many of our stores. Visit one of our 8 locations in the United Kingdom today to learn more.