Allowance For Bending Sheet Metal

When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.

Allowance for bending sheet metal.

Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. We will start by calculating the bend allowance. The bend table approach is probably the most accurate approach for calculating bend allowance. This page also includes a link to a on line sheet metal bend allowance calculator.

Bend allowance is a measure of how much extra material is required to accommodate a bend in sheet metal this is a function of the bend angle bend radius thickness of the material and a variable called the k factor bend allowances vary based on the angle of the bend the type and thickness of the material and the method used to create the. Therefore the bend allowance added to the flange lengths is equal to the total flat. Most sheet metal materials will conform to the calculations. August 29 2020.

As this happens you gain a small amount of total length in your part. Understanding the bend allowance and consequently the bend deduction of a part is a crucial first step to understanding how sheet metal parts are fabricated. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal.

The force must exceed the material s yield strength to achieve a plastic deformation. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched. From there we can calculate the k factor and the bend deduction. 90 degrees bend angle.

Childress last modified date. After bending the sheet we need to do some measurements as shown in figure 2. Commonly used equipment include box and pan brakes brake presses and other specialized machine presses typical products that are made like this are boxes such as electrical enclosures and rectangular ductwork. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length.

Sheet metal calculator bend allowance equations and calculator. This is done through the application of force on a workpiece. Understanding the bend allowance and consequently the bend deduction of a part is a crucial first step to understanding how sheet metal parts are fabricated. Bending is a manufacturing process that produces a v shape u shape or channel shape along a straight axis in ductile materials most commonly sheet metal.

Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape. The value of the bend allowance that comes from sheet metal suppliers and manufactures as well as engineering textbooks are provided in bend tables and bend table looks pretty much like the following excel spreadsheet. Cells on the right will output the desired values.