Bend Allowance Table For Sheet Metal

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.

Bend allowance table for sheet metal.

The material thickness will be measured in decimal form not by the gauge number. The bend allowance bend deduction of the sheet metal specified in k factor by configuring and utilizing a sheet metal gauge table we can speed up the process of selecting the correct wall thickness based on gauge value and selecting the correct bend radius based on available tooling we can also automate the process of selecting the. V die width is 6 8 times the plate thickness none 90 bend 180 angle 90 deduction the deduction is 1 8 times the steel plate thickness and 1 6 times the aluminum plate. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length.

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 bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. It exists for a reason. 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.

None 90 bend unfold according to the neutral layer the distance from neutral to sheet inner side is t 3 inner r can refer to the above chart. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. We will start by calculating the bend allowance.

Table 1 preferred recommended 90 degree bend radii for various sheet metals. After bending the sheet we need to do some measurements as shown in figure 2. Sheet metal bend radii if these guidelines are not followed more research and or some form of analysis may be requried. If you design your bent sheet metal parts in cad software that has a special sheet metal environment use it.

Bend allowance and k factor. From there we can calculate the k factor and the bend deduction.