Bending Sheet Metal Rules

As a general recommendation 0 005 in.

Bending sheet metal rules.

Grain structure in the metal sheet is critical for avoiding cracks in sheet metal parts with lugs or tabs that are cut on. Bending is a process whereby a force is applied to sheet metal which causes it to bend at an angle and form the desired shape. Sheet metal bending should be as perpendicular as possible to the direction of the metal fiber. Relief height is generally kept greater than two times of sheet thickness plus bend radius.

When the sheet metal bend is parallel to the direction of the fiber of the metal material cracks are likely to occur at the bend of the sheet metal and the bending strength is low and it is easy to break as shown in the following figure. Bend relief is provided at the end of bending edge in sheet metal design to avoid any crack tearing in the corner. As a result the wipe die also determines the bend s inner radius. Bend relief and collars near pierced areas strengthen sheet metal parts.

Wipe bending or edge bending is another way to bend sheet metal edges. Bending is performed by a press brake machine that can be automatically or manually loaded. Here s a good rule of thumb for most materials. Runs right at the limit of precision flat sheet metal in a job shop environment.

It is important to make sure that the sheet is properly pushed onto the wipe die. There is no particular rule for how much the material should be weakened but as a rule of. Bends can be short or long depending on what the design requires. As per sheet metal design thumb rules the depth of bend relief should be greater than or equal to the inside bend radius of the bend and the width of the bend relief should be the same as the sheet metal thickness or more.

Extrude hole size position guidelines creating an extruded hole using a punching process requires extreme pressure force. If you re bending 0 020 thick material use a 0 020 radius. The slack between the wipe die and the punch plays an important role in getting a good result. Once the plate is bent to the target angle the material will bounce back to its original shape once the pressure is removed due to tensile stress and compressive stress.

In other words if you re bending 1 8 sheet use a tool with a 1 8 radius to form the inside of the bend. When slotting sheet metal at the bend axis the material s average density in the bend region is decreased.