Bending Sheet Metal 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.

Bending sheet metal bend allowance.

From there we can calculate the k factor and the bend deduction. The material thickness will be measured in decimal form not by the gauge number. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. Bending is one of the most common sheet metal fabrication operations.

The bend deduction is the amount the sheet metal will stretch when bent as measured from the outside edges of the bend. 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. Bend allowance is a measure of how much extra material is required to accommodate a bend in sheet metal. Sheet metal calculator bend allowance equations and calculator.

The bend allowance region is shown in green in my diagram this is a region wherein theory all deformation occurs during the bending process. This page also includes a link to a on line sheet metal bend allowance calculator. The bend radius refers to the inside radius. Bend allowance is the amount of metal to be added to the total layout.

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. We will start by calculating the bend allowance. This is a function of the bend angle bend radius thickness of the material and a variable called the k factor.

The most important considerations when bending metal is the min. You only have to insert interior angle flange lengths k factor inside radius and material thickness. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. Most sheet metal materials will conform to the calculations.

After bending the sheet we need to do some measurements as shown in figure 2. When bends are made smaller than the required min. When sheet metal is bent it stretches in length. Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape.

Radius metal will crack at the outside heel of the bend. This is done through the application of force on a workpiece. 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. Radius of a bend is determined by the hardness and thickness of the metal.

The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. Cells on the right will output the desired values.