Bend Allowance Table For 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.

Bend allowance table for sheet metal.

Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. The required die width is 12 mm and tonnage per meter is 22. Most sheet metal materials will conform to the calculations.

The material thickness will be measured in decimal form not by the gauge number. 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 tables below show bend radii and minimum bend sizes for materials and tooling combinations stocked by protocase. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length.

Calculate unfold size with bend allowance chart. We will start by calculating the bend allowance. 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 appropriate k factor. The lowest common bench capacity is around 100 tonnes.

Bend forming 0 l a b 0 43t t thickness deduction 0 43t. Table 1 preferred recommended 90 degree bend radii for various sheet metals. From there we can calculate the k factor and the bend deduction. This page also includes a link to a on line sheet metal bend allowance calculator.

Therefore the bend allowance added to the flange lengths is equal to the total flat length. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. My workpiece s bending line is 3 m so the overall needed force is 3 22 66 tonnes. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.

Therefore even a simple bench with enough room to bend 3 m pieces will do the job. It is possible to choose other bends but tooling charges may apply. To use the tables below. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.