Bend Deduction Formula Sheet Metal Bending

The flatten length of the parts that are lf equals d1 plus d2 minus the bend deduction.

Bend deduction formula sheet metal bending.

Cells on the right will output the desired values. Sheet metal flat length can be calculated in the following three simple steps. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched. 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.

Bend allowance ba π 180 r k t a. 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. In the example above it is indicated by a dashed blue line. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend.

When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched. We will start by calculating the bend allowance. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. Understanding the bend deduction and consequently the bend allowance of a part is a crucial first step to understanding how sheet metal parts are fabricated.

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. 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. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. Bd bend deduction.

Sheet metal calculator bend allowance equations and calculator. Therefore the bend allowance added to the flange lengths is equal to the total flat. The bend allowance is the amount of the neutral axis that bends. If the value of sheet metal k factor and bending flange length is known.

After bending the sheet we need to do some measurements as shown in figure 2. Calculate the value bend allowance for required sheet metal bend by using below formula. Lf d1 d2 bd. As with bend allowance bend deduction comes from the same sources tables and manual testing.

As this happens you gain a small amount of total length in your part. In the example above it is indicated by a dashed blue line. From there we can calculate the k factor and the bend deduction. The formula is as follows.

This page also includes a link to a on line sheet metal bend allowance 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. Most sheet metal materials will conform to the calculations.