Calculating Developed Length For Sheet Metal Bends

The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length.

Calculating developed length for sheet metal bends.

Sheet metal flat length can be calculated in the following three simple steps. Calculate the value bend allowance for required sheet metal bend by using below formula. Bend allowance ba π 180 r k t a. Where ba is bend allowance.

You only have to insert interior angle flange lengths k factor inside radius and material thickness. We know that ba is the length of the arc on the neutral axis. Ba bend angle π 180 r k factor t eqn 1. Ultimate tensile strength psi.

The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. We can calculate the leg length 1 and 2 as follows. Cells on the right will output the desired values. By replacing initial length leg length 1 and 2 in the above equation we can calculate the bend allowance as follows.

With this free online tool we quickly get the sheet metal bend deduction and therefore the sheet metal blank initial flat length from the finished part measurements. Punch edge radius in. In this formula the initial length is 300 mm. Die edge radius in.

At the neutral axis we have. The formula for calculating sheet metal bending allowance is please refer to the above picture. R is inner bend radius.