One option among metal fabrication methods is the press brake machine. Powered press brakes have been around for almost a century, though manually operated brakes were first invented several decades earlier. The press brake is a great tool for bending or shaping metal plates or sheets rapidly and safely, particularly for high volume production programs.
While the earliest machines were quite simple, modern press brakes can be impressive in terms of both size and performance, with the largest devices capable of handling sheets that are several meters wide.
What is a press brake?
A press brake is a fabrication machine that shapes metal sheet and plate. It works by creating predetermined bends in material placed between an upper and lower die. Force is applied to the die and the metal bends at the desired point. Depending on the machine and the type of die being used, there are a variety of shapes that can be created.
The basic design of most press brake machines starts with a robust press frame made up of two outside uprights, a worktable across the bottom and connecting plate across the top. There are two tools, one attached to the table and the other attached to the ram. The ram consists of a whole steel plate positioned above the worktable between the uprights; the upper die is attached to the ram’s lower edge and cycles downward to force the workpiece into the lower die and initiate the desired angle. A press brake is usually described by the type of force that’s being applied; there are mechanical, pneumatic, hydraulic and servo-electric press brakes.
A mechanical press, which was the most popular option until the 1950’s, uses a flywheel with an electric motor. The operator employs a clutch that engages the flywheel and powers the crank mechanism forcing the ram down. Mechanical presses offer both speed and accuracy, making them an efficient machine for simpler jobs.
A hydraulic press employs two synchronized hydraulic cylinders that are attached to the uprights and move the ram. A servo-electric press has a servomotor that propels a ball screw or belt drive, which then applies pressure to the ram. Finally, a pneumatic press operates thanks to air pressure that forces the ram into the workpiece.
Among modern machines, pneumatic and servo-electric press brakes are best suited for applications that require a lower amount of force. Hydraulic press brakes are extremely accurate and do not consume a lot of energy, making them a good option when sustainable operations are a priority. Another benefit is that the action of the ram can be halted on command, making them extremely safe.
Modern press brakes have increased automation and CNC controls, allowing for greater precision and repeatability compared with traditional machines. It’s not unusual for contemporary devices to come with multi-axis computer-controlled back gauges, optical sensors, and programmable controls that use real-time data to inform the machine when to make adjustments without an operator needing to intervene.
What types of dies can be used with press brakes?
In addition to the different types of mechanics, a great deal of variety in press brake metal fabrication comes from the type of die that is employed. The most common dies are known as V-dies, in which the bottom of the die has a V-shaped depression. V-dies can come in many different sizes and angles, allowing for a wide diversity of finished bends.
Other types of dies include the following:
- Rotary bending dies
- 90 degree dies
- Acute angle dies
- Gooseneck dies
- Offset dies
- Hemming dies
- Seaming dies
- Radius dies
- Beading dies
- Curling dies
- Tube- and pipe-forming dies
- Four-way die blocks
- Channel-forming dies
- U-bend dies
- Box-forming dies
- Corrugating dies
- Multiple-bend dies
- Rocker-type dies
What other factors are important for press brakes?
One of the most important considerations a fabricator must be aware of when it comes to press braking is the tonnage required. Another way of describing this is the bending force, or the amount of pressure applied on the workpiece. The tonnage of a machine indicates exactly how much pressure the ram can apply. The more pressure, the thicker and harder the metal that can be bent. When bending stainless steel plate, a much higher tonnage will be needed compared to thin aluminum sheet.
The other key specifications are the dimensions of the metal being bent. A press brake’s bending length tells the operator what the maximum length of the sheet is.
Your Press Break Metal Fabrication Professional
While the principles behind press braking are quite simple, there is a lot of nuance involved, especially when it comes to picking out the right alloy for any given application. By working with Clinton Aluminum, the Midwest’s leading supplier of aluminum and stainless steel, our customers can rest easy knowing that we’ll be available through every step of their procurement process. We are dedicated to providing premium stainless steel and aluminum plate and sheet for our customers.
Our knowledgeable and friendly customer service team is happy to discuss your plate and sheet needs and answer any questions that you might have. Contact us today to learn more.