Consider a sheet with a 20 mm thickness and a length of 300 mm as shown in figure 1.
Sheet metal k factor chart pdf.
The inside radii are based off of a standard air bend force chart.
The k factor is defined as the ratio between the material thickness t and the neutral fibre axis t i e.
60 90 and 120 and we will calculate k factor bend allowance and bend deduction for them.
Since the inside compression can not exceed the outside tension the k factor can never exceed 50 in practical use.
The below microsoft excel chart is for even numbered gauges 8 through 24 and has a default k factor of 33 for each.
We are going to review three bending scenarios with three different bending angles.
The inside radii are based off of a standard air bend force chart.
A k factor will typically range between 0 and 5 for standard materials and thicknesses though smaller and larger k factors are possible.
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.
Calculate k factor bend allowance and y factor for sheet metal bending.
Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape.
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.
The k factor is fundamental to designing precise sheet metal products.
The below chart is for even numbered gauges 8 through 24 and has a default k factor of 33 for each.
The part of the material that bends.
Press brake bend allowance chart.
For example if the value of k factor for given material thickness and bending machines is known.
The k factor is usually somewhere between 0 3 and 0 5.
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.
Sheet metal bending methods design tips k factor bending is one of the most common sheet metal fabrication operations.
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.
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.
You can easily modify the material thickness inside radius and k factor for each thickness at the top of each column.
Sheet metal flat length can be calculated using cad softwares.
Sheet metal bend allowance chart pdf.
K factor in sheet metal bending is a constant that is used to calculate sheet metal flat length.
Therefore using k factor there is no need to calculate sheet metal flat length manually.