Sheet Metal Forming Bend Radius

Where ossb is the outside setback.

Sheet metal forming bend radius. As explained in my first post the bend deduction can be calculated using the following equation. Wipe bending or edge bending is another way to bend sheet metal edges. When bending a piece of sheet metal the residual stresses in the material will cause the sheet to springback slightly after the bending operation. Due to this elastic recovery it is necessary to over bend the sheet a precise amount to achieve the desired bend radius and bend angle.

Use this document to choose values that are both manufacturable and meet your needs. Most frequently expensive sheet metal bending tools called brakes are used to bend sheet metal but you can also complete this task without one. It is possible to choose other bends if you require but additional lead time and tooling charges may apply. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance.

Where a is the bending angle t is the sheet thickness and r is the bending radius. The bend radii listed are standard minimum if manufacturing for aircraft and aerospace applications. It is important to make sure that the sheet is properly pushed onto the wipe die. It is most economical to use a single bend radius throughout the design but if necessary you can utilize multiple radii.

You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. The slack between the wipe die and the punch plays an important role in getting a good result. As a result the wipe die also determines the bend s inner radius. Bend radii minimum bend sizes.

Bending sheet metal by hand is a manageable task if the piece of sheet metal is small and thin enough to handle. The material thickness will be measured in decimal form not by the gauge number. Minimum sheet metal flange bend length is required to avoid cracks in the bending area. The tables below show bend radii and minimum bend sizes for materials and tooling combinations stocked by protocase.

Use the known k factor and the known inner bending radius to calculate the bending radius of the neutral line. In sheet metal design the k factor is used to calculate how much sheet metal one needs to leave for the bend in order to achieve particular final dimensions especially for between the straight sides next the bend. It shall be equal to three times of sheet thickness plus bend radius. Minimum sheet metal flange bend length 3 x sheet thickness bend radius.

Since commercial sheet metal bending can be done with less concern for stresses caused during forming operation the radius can be near zero for thin sheet metal.