Bend Allowance For Aluminum Sheet

We will start by calculating the bend allowance.

Bend allowance for aluminum sheet.

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. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. Most sheet metal materials will conform to the calculations. V die width is 6 8 times the plate thickness.

Calculate unfold size with bend allowance chart. Therefore the bend allowance added to the flange lengths is equal to the total flat. From there we can calculate the k factor and the bend deduction. 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. This page also includes a link to a on line sheet metal bend allowance calculator. The value of the bend allowance that comes from sheet metal suppliers and manufactures as well as engineering textbooks are provided in bend tables and bend table looks pretty much like the following excel spreadsheet. When making bends it takes material specifications into account.

Bend allowance and k factor. L unfold length a outside size b outside size k k factor none 90 bend unfold according to the neutral layer the distance from neutral to sheet inner side is t 3 inner r can refer to the above chart. Bending is a manufacturing process that produces a v shape u shape or channel shape along a straight axis in ductile materials most commonly sheet metal. After bending the sheet we need to do some measurements as shown in figure 2.

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 bend. Sheet metal calculator bend allowance equations and calculator. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. Bend forming 0 l a b 0 43t t thickness deduction 0 43t.

The bend table approach is probably the most accurate approach for calculating bend allowance. 90 degrees bend angle. Commonly used equipment include box and pan brakes brake presses and other specialized machine presses typical products that are made like this are boxes such as electrical enclosures and rectangular ductwork. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal.

If you design your bent sheet metal parts in cad software that has a special sheet metal environment use it. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.