Bend Allowance Table For Sheet Metal

Bend allowance and k factor.

Bend allowance table for sheet metal.

The bend table approach is probably the most accurate approach for calculating bend allowance. When making bends it takes material specifications into account. The material thickness will be measured in decimal form not by the gauge number. 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.

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 formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. Table 1 preferred recommended 90 degree bend radii for various sheet metals. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.

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. Sheet metal bend radii if these guidelines are not followed more research and or some form of analysis may be requried. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees.

We will start by calculating the bend allowance. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length. 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.

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. If you design your bent sheet metal parts in cad software that has a special sheet metal environment use it.