Bend Allowance Formula In Sheet Metal

Most sheet metal materials will conform to the calculations.

Bend allowance formula in sheet metal.

The bend allowance is the amount of the neutral axis that 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. Ba bend allowance. Childress last modified date.

In the example above it is indicated by a dashed blue line. Sheet metal calculator bend allowance equations and calculator. It is better to solve some formula based examples to really understand the fabrication formulas for sheet metal bend allowance ba the amount of material added to the sum of the two leg lengths to obtain the flat pattern 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.

August 29 2020. There is sheet metal software available that performs all calculations automatically like solidworks and litio. Adding the length of each flange taken between the center of the radius to the ba gives the. If you have a sheet metal bending product as shown in above picture with two legs of length x and y and you unbend it you will see that total length of the unbend sheet will not x y rather the length will be x y ba.

Consider a sheet with a 20 mm thickness and a length of 300 mm as shown in figure 1. Lf l1 l2 ba. We are going to review three bending scenarios with three different bending angles. 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.

The material thickness will be measured in decimal form not by the gauge number. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. 60 90 and 120 and we will calculate k factor bend allowance and bend deduction for them.

Therefore the bend allowance added to the flange lengths is equal to the total flat. The bend allowance method is based on the formula that i ve got appear in my diagram. This page also includes a link to a on line sheet metal bend allowance calculator. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.

The bend allowance ba is the length of the arc of the neutral line between the tangent points of a bend in any material. In the example above it is indicated by a dashed blue line.