Bend Deduction Formula Sheet Metal Bending

The material thickness will be measured in decimal form not by the gauge number.

Bend deduction formula sheet metal bending.

The material thickness will be measured in decimal form not by the gauge number. Lf d1 d2 bd. Geometry of tooling imposes a minimum bend dimension. Therefore the bend deduction equals the difference between the mold line lengths and the total flat length.

The values of the setback bend allowance and bend deduction can be calculated from the sheet thickness bend radius bend angle and k factor. 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. As with bend allowance bend deduction comes from the same sources tables and manual testing. Calculate the value bend allowance for required sheet metal bend by using below formula.

Bend allowance ba π 180 r k t a. Most sheet metal materials will conform to the calculations. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. You only have to insert interior angle flange lengths k factor inside radius and material thickness.

You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. In machinery s handbook the k factor for mild cold rolled steel with 60 000 psi tensile strength is 0 446 inch. The formula is as follows. With this free online tool we quickly get the sheet metal bend deduction and therefore the sheet metal blank initial flat length from the finished part measurements.

Refer to the chart for values for folder as well as various press brake tooling combinations. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. The mold line lengths are the distances measured to the outside mold line and are equal to the flange lengths plus the setback. This page also includes a link to a on line sheet metal bend allowance calculator.

Bd bend deduction. Where ossb is the outside setback. Another method that solidworks uses is the bend deduction method. Where a is the bending angle t is the sheet thickness and r is the bending radius.

Use the minimum bend dimension values in the charts below for your minimum closeness of cutout to a bend. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. As explained in my first post the bend deduction can be calculated using the following equation. Sheet metal calculator bend allowance equations and calculator.

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. Ossb is defined as illustrated in figure 5 for different bending angles and can be calculated using the equation below. Learn more about bending.

Cells on the right will output the desired values.