Calculating Developed Length For Sheet Metal Bends

If the value of sheet metal k factor and bending flange length is known.

Calculating developed length for sheet metal bends.

By replacing initial length leg length 1 and 2 in the above equation we can calculate the bend allowance as follows. Cells on the right will output the desired values. Where ba is bend allowance. 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.

R is inner bend radius. We know that ba is the length of the arc on the neutral axis. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. In this formula the initial length is 300 mm.

You only have to insert interior angle flange lengths k factor inside radius and material thickness. Ba bend angle π 180 r k factor t eqn 1. Therefore the bend allowance added to the flange lengths is equal to the total flat length. Bend angle represents the angle to which sheet metal has bend here it is 90 degree.

Punch edge radius in. The formula for calculating sheet metal bending allowance is please refer to the above picture. Die edge radius in. Calculate the value bend allowance for required sheet metal bend by using below formula.

We can calculate the leg length 1 and 2 as follows. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length. At the neutral axis we have.