Bend Deduction Formula Sheet Metal Bending

The formula is as follows.

Bend deduction formula sheet metal bending.

Bd bend deduction. The material thickness will be measured in decimal form not by the gauge number. The mold line lengths are the distances measured to the outside mold line and are equal to the flange lengths plus the setback. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal.

The material thickness will be measured in decimal form not by the gauge number. You only have to insert interior angle flange lengths k factor inside radius and material thickness. As with bend allowance bend deduction comes from the same sources tables and manual testing. Ossb is defined as illustrated in figure 5 for different bending angles and can be calculated using the equation below.

The bend deduction formula takes into account the geometries of bending and the properties of your metal to determine the bend deduction. Calculate the value of bend deduction from the values of bend allowance and outside setback. Learn more about bending. Where a is the bending angle t is the sheet thickness and r is the bending radius.

As explained in my first post the bend deduction can be calculated using the following equation. Cells on the right will output the desired values. Most sheet metal materials will conform to the calculations. Refer to the chart for values for folder as well as various press brake tooling combinations.

Where ossb is the outside setback. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. Lf d1 d2 bd. Therefore the bend deduction equals the difference between the mold line lengths and the total flat length.

In machinery s handbook the k factor for mild cold rolled steel with 60 000 psi tensile strength is 0 446 inch. Sheet metal calculator bend allowance equations and calculator. The diagram shows one such mechanism. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.

Calculate the value bend allowance for required sheet metal bend by using below formula. Bend allowance ba π 180 r k t a. The flatten length of the parts that are lf equals d1 plus d2 minus the bend deduction. Ba 0 017453 inside radius 0 0078 material thickness bend angle which is always complementary the length of the neutral axis is calculated as a bend allowance taken at 50 percent of the material thickness.

Geometry of tooling imposes a minimum bend dimension. This page also includes a link to a on line sheet metal bend allowance calculator. The values of the setback bend allowance and bend deduction can be calculated from the sheet thickness bend radius bend angle and k factor. Bend allowance bend deduction 2 ossb.

You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.