Press Brake Tooling Styles
Press brake tooling includes dies and punches used with a press brake to form, bend or flatten sheet metal.
Press brake tools are used in conjunction with a press brake, which operates are heavy boom or press in order to shape and bend sheet metal. The press uses a punch to force the metal sheet into the die, creating a permanent crease and reshaping the metal. Press brakes and their accompanying tools operate without an external heating device; the heat and friction from the press tools are enough to reshape the material. Press brake tools are usually steel, but other materials such as urethane do exist.
Below are punch and die configurations used to provide a variety of bends for sheet metals:
Press Brake Complications
- Anisotropy: Sheet metal is produced by a rolling process that stretches the metallic crystal structure across the length of the sheet. This can alter the malleable characteristics of each individual sheet.
- Springback: Near the center of the bend is a low-stress zone where only elastic deformation occurs. After a bend, this area retains some of its original shapes. Stiffer sheets have higher levels of spring back, but press brakes can be made to account for spring back.
- Galling: Occasionally, metal flakes or particles can become stuck to the punch during the bending process. If not removed, this can modify the bend and damage the sheet.
- Machine deflection: When high pressure is exerted the top tool may become misaligned from the bottom tool, resulting in an uneven bend across the sheet. This can be fixed with automated adjustment systems.
Some manufacturers provide the maximum allowable tonnage that can be applied to press break tools. In instances where this is not provided, as safe rule of thumb is to never apply a press’ full tonnage to a length less than 60% percent of the side frames. Doing so could cause a small section to be overloaded, deforming the material, press and tooling.