Bending radius: the ultimate guide

Press brake is one of the most important tools in sheet metal processing. When using a press brake to process sheet metal, the bending radius is a key factor affecting the bending effect. In this article, we will give an overview of the bending radius of sheet metal.

Ⅰ. What is the bending radius of sheet metal?

The bending radius of sheet metal refers to the radius of the inner curve formed by the material when it is bent during sheet metal processing. This radius is very important to ensure that the bent parts have good appearance and structural strength. The size of the bending radius affects the stress distribution of the material, the accuracy of the bending angle, and the difficulty of subsequent processing.

Ⅱ. What determines the bending of sheet metal?

1. Material type

Different materials (such as aluminum, stainless steel, carbon steel, etc.) have different ductility and strength, which affects the required bending radius. Flexible materials can use a smaller bending radius, while materials with higher hardness require a larger radius.

2. Material thickness

Generally speaking, the thicker the material, the larger the bending radius should be to avoid material cracking or undesirable stress concentration

3. Bending angle

The larger the bending angle, the larger the bending radius may be required to ensure that the material will not crack or deform during the bending process.

4. Processing technology

Different bending processes (such as air bending, bottom die bending, etc.) have different requirements for bending radius. Process parameters such as bending speed and pressure will also affect the final bending radius.

5. Mold design

The shape and design of the mold determine the stress of the material during the bending process. A good mold can help achieve the required bending radius

6. Subsequent processing requirements

If the subsequent processing (such as welding, painting, etc.) has specific requirements for the bending radius, these factors need to be considered to select the appropriate radius

Ⅲ. Bending radius calculation of Press Brake

First, select the mold opening according to the 8-fold rule. It is recommended that the V-shaped mold opening should be 8 times the material thickness. The size of the mold opening directly affects the bending radius.

While there is no exact formula to determine the ideal bending radius for sheet metal, it can be estimated that the bend radius is equal to the sheet thickness under certain specific force conditions.

It is important to note that variations in material thickness can affect the accuracy of this estimate. The V-die opening can be 6 to 12 times the material thickness. The bend radius is closely related to the material thickness. For material thicknesses less than 6 mm, the bend radius is equal to the material thickness.

For material thicknesses greater than 6 mm but less than 12 mm, the bend radius is generally 1.5 times the material thickness. For material thicknesses greater than 12 mm, the bend radius is approximately 3 times the material thickness.

The bending radius of the press brake can be calculated using the formula, all in millimeters:

r = (v - mt) / 2

- R is the bending radius

- V is the width of the V-shaped opening of the die

- MT is the material thickness

For example: if the die opening is 30mm and the plate thickness is 3mm, the bending radius is R=(30-3)/2=13.5mm

It is important to know that these are only rough guidelines, and there are many factors that affect the bending radius, so it is difficult to determine an exact number. When the plate thickness is equal to the bending radius, the optimal bending radius is achieved. The bend formed with this radius is consistent in angle and size, and the springback is minimal.

IV. What is the minimum bending radius of sheet metal

The smaller the bending radius, the greater the bending pressure required. Sheet metal is very prone to cracking, deformation or breaking during the bending process, and it is also easy to damage the mold. To avoid these problems, we should pay attention to the minimum inner bending radius.

Due to the different characteristics of bending methods, materials and molds, the minimum bending radius should also be paid attention to. In order to obtain a perfect sheet metal product, try to make the inner radius of the bend close to the thickness of the plate.

Choose sheet metal materials with high ductility. The greater the tensile strength and hardness of the sheet metal, the greater the bending pressure required.

The bending radius plays a vital role in sheet metal bending. The correct inner radius ensures the bending quality of the workpiece. The wrong inner radius of sheet metal bending can cause the workpiece to deform or even break. This article provides an overview of sheet metal bending. The use of ZYCO Press Brake helps to produce more precise workpieces. If you have any questions about large radius bending or any other type of sheet metal bending on a bending machine, please contact us.