Bend Allowance For Aluminum Sheet

90 degrees bend angle.

Bend allowance for aluminum sheet.

Calculate unfold size with bend allowance chart. 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. 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. When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched.

Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. V die width is 6 8 times the plate thickness. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. Bend allowance and k factor.

When the sheet metal is put through the process of bending the metal around the bend is deformed and stretched. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length. This page also includes a link to a on line sheet metal bend allowance calculator. If you design your bent sheet metal parts in cad software that has a special sheet metal environment use it.

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. 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. 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. The bend table approach is probably the most accurate approach for calculating bend allowance.

Most sheet metal materials will conform to the calculations. As this happens you gain a small amount of total length in your part. After bending the sheet we need to do some measurements as shown in figure 2. When making bends it takes material specifications into account.

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. Therefore the bend allowance added to the flange lengths is equal to the total flat. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. It exists for a reason.

We will start by calculating the bend allowance. Bend forming 0 l a b 0 43t t thickness deduction 0 43t.