Bend Allowance Formula In Sheet Metal

You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.

Bend allowance formula in sheet metal.

Bend allowance is a measure of how much extra material is required to accommodate a bend in sheet metal this is a function of the bend angle bend radius thickness of the material and a variable called the k factor bend allowances vary based on the angle of the bend the type and thickness of the material and the method used to create the. 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. Most sheet metal materials will conform to the calculations. In the example above it is indicated by a dashed blue line.

There is sheet metal software available that performs all calculations automatically like solidworks and litio. 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 ba is the length of the arc of the neutral line between the tangent points of a bend in any material. Childress last modified date.

The bend allowance method is based on the formula that i ve got appear in my diagram. Adding the length of each flange taken between the center of the radius to the ba gives the. We are going to review three bending scenarios with three different bending angles. August 29 2020.

Consider a sheet with a 20 mm thickness and a length of 300 mm as shown in figure 1. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. Ba bend allowance. Sheet metal calculator bend allowance equations and calculator.

Where ba is bending allowance. The material thickness will be measured in decimal form not by the gauge number. Lf l1 l2 ba. In the example above it is indicated by a dashed blue line.

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. This page also includes a link to a on line sheet metal bend allowance calculator. The bend allowance is the amount of the neutral axis that bends. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal.

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