A Layman's Guide on How to Bend Metal Sheets

How to Bend Metal Sheets
Press brakes are the tools most helpful in bending metal sheets. Most bending machines are manufactured to meet industry needs.
Press brakes are commonly used to bend metal sheets for various industrial purposes. A press brake is a machine that applies direct pressure on the metal sheet and alters it to the desired shape. It is widely used all over the world to mold all types of metals into varying shapes. Metal fabrication work such as welding, making aluminum windows or custom-made metal parts for cars and trucks cannot be done unless you have a brake at your disposal.

Brakes

In general, a brake (sheet metal bending machine ) has a flat surface, a holding bar and a gate-like plate hinged perpendicular to the plane on which rests the metal sheet. The metal sheet is kept on the flat surface and the holding bar is then placed over the top of the sheet to prevent it from moving while bending. Depending upon the type of brakes, the holding bar can produce a clamping force of about 6 tons. The line along which the bent is to be initiated is then placed at the intersection of plate and the flat surface. The plate is then moved upwards (manually or automatically) along the hinges to a certain degree in order to bend the metal sheet at the desired angle.

Bending Metal Sheets Using Press Brakes

A sheet of metal is inserted into the jaws of press brakes and then with the help of a long lever, the metal is bent to the desired angle. The metal should be bent considering the ductility of the metal. Ductility means the amount of pressure that can be applied on the metal without breaking or fracturing it. Before inserting the metal, you should have a clear idea about how you want to bend the metal sheet and the number of bends required for your product design.

Hydraulic Press Brakes

There are different types of press brakes such as manually operated, pneumatic press brakes and more. However, the most popular ones are the hydraulic press brakes. They significantly cut the labor requirement, thereby reducing the labor cost and deliver a superior performance than the mechanical ones. As these machines operate at a high-speed, productivity naturally increases, thus allowing you to do more jobs in less time. Other advantages like low energy consumption, high reliability and quality of manufactured products and a lower risk of injury, make these machines ideal for bending metals. Hydraulic press brakes can effectively handle tough industrial jobs including single cycle operations. These tools provide reliable results with better accuracy.

Bending Metals Using Rolling Process

There are machines that employ a rolling process to bend metal sheets. The rollers rotate in opposite direction at the same speed. When a great deal of bending is required, this method is quite effective as it can make bends up to 360 degrees. As the metal passes through the set of rollers, the turning rollers and the machine apply pressure to bend the metal sheet to achieve the desired radius. This method is often used when it comes to producing spiral staircases and stainless steel coils.

Brakes With CNC Controls

With the advancement in technology, today's press brakes come with CNC controls that allow you to form metal parts with great accuracy. These machines are computer controlled and fully automated. They have extensive bending capability that allow you to bend the desired sections of the metal sheet. A sensor is also installed to monitor the entered angle of bending. These machines have a user interface where you need to enter the bending sequence of operations. With each passing day, machines are being equipped with more programmable features, making the job of the operator simpler. There are bending machines that can literally bend metal to any angle.

The Box and Pan Brake

As aforementioned, there are different types of metal bending brakes and each one is designed to cater a specific purpose. Transforming a metal sheet into a box is something that cannot be achieved using regular type brakes. For instance, a 90 degree bending angle has to made at different parts of its length, without which a metal enclosure cannot be made. In order to create an open metal cube, 4 perpendicular bends are necessary. Making multiple bends at different places of the sheet, is done using box and pan brake.

In a box and pan machine, the holding bar is not one single bar but made up of multiple blocks that can be removed easily. As per the requirement, you may use only a few blocks to clamp a specific part of the sheet to get a 90 degree fold in that area. The entire holding bar is never used in this machine as only a small portion of the sheet requires perpendicular bending.

Bending Metal Sheets At Home

It is also possible to bend a metal sheets without using press breaks. A vise is often used at home for bending the metal sheets. A vise, attached to a workbench, is a device that is used for holding objects. It has 2 jaws that hold the workpiece firmly in place. You will also require a butane torch, a set of pipe pliers and a protractor, to judge the brake as you slowly start bending the metal. Put the metal sheet into the jaws of the vise. Now lower the jaws and using the butane torch, warm the section of the metal where you want the bend. As the heated section cools off, pull the metal sheet towards you with the help of pliers.

Before operating these machines, it is essential to take all safety measures as the injuries sustained due to press brakes can be dangerous. Equip yourself with gloves and eye protection whenever working with vise and press brakes.