The formula is as follows.
Bend deduction formula sheet metal bending.
After bending the sheet we need to do some measurements as shown in figure 2.
When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.
Lf d1 d2 bd.
Although it is an option for calculating a bend in some cad programs such as solid works it is not often referred to in the actual manufacturing process since.
As this happens you gain a small amount of total length in your part.
We will start by calculating the bend allowance.
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.
You only have to insert interior angle flange lengths k factor inside radius and material thickness.
The flatten length of the parts that are lf equals d1 plus d2 minus the bend deduction.
Bd bend deduction.
Calculate the value bend allowance for required sheet metal bend by using below formula.
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 deduction and consequently the bend allowance 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.
Most sheet metal materials will conform to the calculations.
When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.
In the example above it is indicated by a dashed blue line.
Sheet metal flat length can be calculated in the following three simple steps.
Another method that solidworks uses is the bend deduction method.
The bend allowance is the amount of the neutral axis that bends.
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.
As with bend allowance bend deduction comes from the same sources tables and manual testing.
If the value of sheet metal k factor and bending flange length is known.
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.
From there we can calculate the k factor and the bend deduction.
In the example above it is indicated by a dashed blue line.
Bend allowance ba π 180 r k t a.
This page also includes a link to a on line sheet metal bend allowance calculator.
Cells on the right will output the desired values.
Sheet metal calculator bend allowance equations and calculator.
Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees.
