The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal.
Bend deduction sheet metal example.
When the bend deduction is calculated we find that it equals 293 in length.
Bd bend deduction.
This page also includes a link to a on line sheet metal bend allowance calculator.
In order to develop the flat pattern we will subtract 293 from 5 to arrive at 4 707.
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.
Another method that solidworks uses is the bend deduction method.
In our example below a part with flange lengths of 2 and 3 with an inside radius of 250 at 90 will have a total length of 5.
The flatten length of the parts that are lf equals d1 plus d2 minus the bend deduction.
When we calculate the bend deduction we find that it equals 293.
The formula is as follows.
As with bend allowance bend deduction comes from the same sources tables and manual testing.
The force must exceed the material s yield strength to achieve a plastic deformation.
Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees.
After bending the sheet we need to do some measurements as shown in figure 2.
Bending is one of the most common sheet metal fabrication operations.
Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape.
Therefore the bend allowance added to the flange lengths is equal to the total flat.
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.
The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend.
This is done through the application of force on a workpiece.
From there we can calculate the k factor and the bend deduction.
Should be subtracted from the flat pattern so the formed part arrives at the desired dimensions.
Sheet metal calculator bend allowance equations and calculator.
In the example below the part has flange lengths of 2 and 3 with an inside radius of 250 at 90 will have a length of 5.
In order to develop the flat pattern we will subtract 293 from 5 to arrive at 4 707.
The bend deduction of means that the material is expected to stretch by that amount during the course of bending.
Lf d1 d2 bd.
When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.
Childress last modified date.
We will start by calculating the bend allowance.
Most sheet metal materials will conform to the calculations.
