To find out what the values mean in terms of wall thickness, tables must be referenced to, like the following ( Examples of sheet metal gauge tables for determining the thickness of a metal from the gauge size. Sheet metal wall thickness can be expressed as a gauge value, for example 10, 12 or 16ga.
This will again depend on the wall thickness of the material and the specific bending method that is being used. It is not important what type of bending is used in the process, the bend radius that is created is what needs to be focused on. This is known as bottom bending, and is one of many ways to form a bend in sheet metal. Once the punch is pressed down, it forces the sheet metal to form to the shape of the die.īoth the die and the punch will both have radii at the peak of their v-shape, and this will determine the type of bend that is formed in the metal. The punch is above the die and sheet metal on the top part of the press. Source: The Fabricatorīy examining this diagram, we can see that the v-shaped die is located at the bottom of the press, while the sheet metal is laid on top of the die. An example of a generic punch and die set up. The bend radius is dependent on two factors the tooling that is being used and the wall thickness of the material.Īn example of one certain tool that could be used to bend the sheet metal is a punch and die set. The bend radius of a material is extremely important when designing and evaluating a sheet metal design. For the purposes of this article, we will assume the K-factor is 0.5 instead of calculating it along the way. The K-factor is the most popular way of calculating the bend allowance and bend deduction, but there are multiple ways that this calculation can be done. Metal is known to deform and stretch in the bending region and this is something that is essential to take into account when designing using sheet metal. The bend allowance and bend deduction refers to how the metal is behaving in the bend region.
The selection of the K-factor can also be automated with the gauge table.