Sheet Metal Bending Radius

Use this document to choose values that are both manufacturable and meet your needs.

Sheet metal bending radius.

Also known as press braking flanging die bending folding and edging this method is used to deform a material to an angular shape. It is most economical to use a single bend radius throughout the design but if necessary you can utilize multiple radii. It shall be equal to three times of sheet thickness plus bend radius. This is putting a simple hem on a curved piece of zinc with a 7ft radius.

You will need to know your material thickness mt the bend angle b the inside radius ir and the k factor k. Bending sheet metal by hand is a manageable task if the piece of sheet metal is small and thin enough to handle. The formed bend radius is dependent upon the dies used the material properties and the material thickness. The bend allowance formula takes into account the geometries of bending and the properties of your metal to determine the bend allowance.

The force must exceed the material s yield strength to achieve a plastic deformation. When sheet metal is bent it stretches in length. 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. Minimum sheet metal flange bend length 3 x sheet thickness bend radius.

The bend deduction is the amount the sheet metal will stretch when bent as measured from the outside edges of the bend. Bending is one of the most common sheet metal fabrication operations. As explained in my first post the bend deduction can be calculated using the following equation. Bend radii minimum bend sizes.

Where a is the bending angle t is the sheet thickness and r is the bending radius. The bend radius refers to the inside radius. Most frequently expensive sheet metal bending tools called brakes are used to bend sheet metal but you can also complete this task without one. Minimum sheet metal flange bend length is required to avoid cracks in the bending area.

Where ossb is the outside setback. The material thickness will be measured in decimal form not by the gauge number. The bend radii listed are standard minimum if manufacturing for aircraft and aerospace applications.