Sheet Metal K Factor Chart Pdf

The part of the material that bends.

Sheet metal k factor chart pdf.

The k factor is usually somewhere between 0 3 and 0 5. To help you begin i ve included a k factor chart below which contains common k factor starting points good for general fabrication for steel aluminum and stainless steel. While modern bend deduction charts now are reasonably accurate historically bend calculation charts both for bend allowances and bend deductions were notorious. K factor in sheet metal bending is a constant that is used to calculate sheet metal flat length.

Calculate k factor bend allowance and y factor for sheet metal bending. Consider a sheet with a 20 mm thickness and a length of 300 mm as shown in figure 1. The inside radii are based off of a standard air bend force chart. Therefore using k factor there is no need to calculate sheet metal flat length manually.

For example if the value of k factor for given material thickness and bending machines is known. You can easily modify the material thickness inside radius and k factor for each thickness at the top of each column. The inside radii are based off of a standard air bend force chart. 60 90 and 120 and we will calculate k factor bend allowance and bend deduction for them.

Sheet metal bending methods design tips k factor bending is one of the most common sheet metal fabrication operations. Sheet metal bend allowance chart pdf. K factor effectively 50 t max 25 t min where the neutral axis is situated in a bend is commonly called the k factor as it is signified as k in the development formulas. Since the inside compression can not exceed the outside tension the k factor can never exceed 50 in practical use.

A k factor will typically range between 0 and 5 for standard materials and thicknesses though smaller and larger k factors are possible. We are going to review three bending scenarios with three different bending angles. Sheet metal flat length can be calculated using cad softwares. 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.

Because of the specific properties of any given metal there is no easy way to calculate that value perfectly hence the chart in figure 2. The below microsoft excel chart is for even numbered gauges 8 through 24 and has a default k factor of 33 for each. The k factor is fundamental to designing precise sheet metal products. It allows you to anticipate the bend deduction for a large variety of angles without having to rely on a chart.

Should you wish to calculate the k factor rather than use a chart you will need some test pieces four or five pieces should do nicely for this purpose. 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 defined as the ratio between the material thickness t and the neutral fibre axis t i e.