Bend Allowance Table For Sheet Metal

The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance.

Bend allowance table for sheet metal. 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 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. Sheet metal bend radii if these guidelines are not followed more research and or some form of analysis may be requried.

My workpiece s bending line is 3 m so the overall needed force is 3 22 66 tonnes. Calculate unfold size with bend allowance chart. L unfold length a outside size b outside size k k factor 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. We will start by calculating the bend allowance.

Therefore the bend allowance added to the flange lengths is equal to the total flat length. 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. The material thickness will be measured in decimal form not by the gauge number.

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. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. Most sheet metal materials will conform to the calculations. The lowest common bench capacity is around 100 tonnes.

The tables below show bend radii and minimum bend sizes for materials and tooling combinations stocked by protocase. It is possible to choose other bends but tooling charges may apply. This page also includes a link to a on line sheet metal bend allowance calculator. 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. From there we can calculate the k factor and the bend deduction. To use the tables below. Bend forming 0 l a b 0 43t t thickness deduction 0 43t.