Allowance For Bending Sheet Metal

90 degrees bend angle.

Allowance for bending sheet metal.

Cells on the right will output the desired values. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend.

Sheet metal calculator bend allowance equations and calculator. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length. 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. With this free online tool we quickly get the sheet metal bend deduction and therefore the sheet metal blank initial flat length from the finished part measurements.

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. 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. You only have to insert interior angle flange lengths k factor inside radius and material thickness.

August 29 2020. The force must exceed the material s yield strength to achieve a plastic deformation. As this happens you gain a small amount of total length in your part. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.

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 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. Childress last modified date.

The bend table approach is probably the most accurate approach for calculating bend allowance. From there we can calculate the k factor and the bend deduction. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. Bending is one of the most common sheet metal fabrication operations.

Therefore the bend allowance added to the flange lengths is equal to the total flat. Most sheet metal materials will conform to the calculations. This is done through the application of force on a workpiece.