Bend Allowance Formula In Sheet Metal

Sheet metal flat length can be calculated in the following three simple steps.

Bend allowance formula in sheet metal.

Ba bend allowance. 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 the example above it is indicated by a dashed blue line. The bend allowance is the amount of the neutral axis that bends.

There is sheet metal software available that performs all calculations automatically like solidworks and litio. We are going to review three bending scenarios with three different bending angles. Lf l1 l2 ba. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal.

Although it is an option for calculating a bend in some cad programs such as solid works it is not often referred to in the actual manufacturing process since. Bend allowance ba π 180 r k t a. So if you got k factor value now you can easily calculate bending allowance. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.

Understanding the bend allowance and consequently the bend deduction of a part is a crucial first step to understanding how sheet metal parts are fabricated. Consider a sheet with a 20 mm thickness and a length of 300 mm as shown in figure 1. 60 90 and 120 and we will calculate k factor bend allowance and bend deduction for them. Most sheet metal materials will conform to the calculations.

There are standard charts available with sheet metal design handbook for calculating k factor ideally it should be 0 5. This page also includes a link to a on line sheet metal bend allowance calculator. But the most accurate way to find out k factor is reverse engineering of a small but same sheet metal sample piece. Sheet metal calculator bend allowance equations and calculator.

The total length of the flatten sheet is equal to the sum of l1 that s the first length and l2 plus the bend allowance. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length. Adding the length of each flange taken between the center of the radius to the ba gives the. Therefore the bend allowance added to the flange lengths is equal to the total flat.

If the value of sheet metal k factor and bending flange length is known. Calculate the value bend allowance for required sheet metal bend by using below formula. The bend allowance method is based on the formula that i ve got appear in my diagram. In the example above it is indicated by a dashed blue line.