Sheet Metal Bending Radius

Bend radii minimum bend sizes.

Sheet metal bending radius.

It is most economical to use a single bend radius throughout the design but if necessary you can utilize multiple radii. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance. Where ossb is the outside setback. It shall be equal to three times of sheet thickness plus bend radius.

The bend deduction is the amount the sheet metal will stretch when bent as measured from the outside edges of the bend. As explained in my first post the bend deduction can be calculated using the following equation. Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape. You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k.

The bend radius refers to the inside radius. Where a is the bending angle t is the sheet thickness and r is the bending radius. This is putting a simple hem on a curved piece of zinc with a 7ft radius. Minimum sheet metal flange bend length is required to avoid cracks in the bending area.

The minimum bend radius data shown in these charts is measured to the inside of the bend. The material thickness will be measured in decimal form not by the gauge number. The force must exceed the material s yield strength to achieve a plastic deformation. Bending sheet metal by hand is a manageable task if the piece of sheet metal is small and thin enough to handle.

Use this document to choose values that are both manufacturable and meet your needs. 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. When sheet metal is bent it stretches in length. Most frequently expensive sheet metal bending tools called brakes are used to bend sheet metal but you can also complete this task without one.

This is done through the application of force on a workpiece. The bend radii listed are standard minimum if manufacturing for aircraft and aerospace applications. Ossb is defined as illustrated in figure 5 for different bending angles and can be calculated using the equation below.