Calculating K Factor Sheet Metal Bending

Sheet metal bending methods design tips k factor bending is one of the most common sheet metal fabrication operations.

Calculating k factor sheet metal bending.

Sheet metal bend allowance chart pdf. What is the k factor. The k factor is defined as the ratio between the material thickness t and the neutral fibre axis t i e. We will start by calculating the bend allowance.

Whereas the outer surface is stretched. As a result overall sheet length increases. The part of the material that bends. As shown in figure 1 below k t t.

Once you know the k factor you can use it to predict the bend allowance for various angles. From there we can calculate the k factor and the bend deduction. Then input the bend angle to get the arc length bend allowance and bend deduction. In order to find the k factor you will need to bend a sample piece and deduce the bend allowance.

Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. The k factor is nothing more than a multiplier that can give you an accurate value for the relocated neutral axis. The below microsoft excel chart is for even numbered gauges 8 through 24 and has a default k factor of 33 for each. And if you know the bend allowance you can extract the k factor from it.

The inside radii are based off of a standard air bend force chart. Best way to calculate k factor in sheet metal is by reverse engineering. Since the k factor is based on the property of the metal and its thickness there is no simple way to calculate it ahead of the first bend. For example if the value of k factor for given material thickness and bending machines is known.

Typically the k factor is going to be between 0 and 5. You can easily modify the material thickness inside radius and k factor for each thickness at the top of each column. The k factor is the ratio between the distance from the neutral layer to the bent inner surface and the thickness of the sheet metal. Therefore using k factor there is no need to calculate sheet metal flat length manually.

K factor in sheet metal bending is a constant that is used to calculate sheet metal flat length. The k factor is a key basic concept in solidworks sheet metal design and must be understood in order to learn sheet metal design and fabrication well. This change in sheet length depends on the position of neutral axis or k factor. Calculate k factor bend allowance and y factor for sheet metal bending.

Sheet metal flat length can be calculated using cad softwares. Input material thickness and and inner radius to get the data of k factor y factor neutral layer. The k factor is the most important and elusive variable of bending because it varies both as a function of the material and according to parameters such as angle and tooling. Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape.

Then input leg length a and b to get the flat size of the sheet.