Press brake working background

Press brake tools description

Depends of the application and requirements of bends there are various geometry shapes for punches and dies of press brake tooling to perform standard or special sheetmetal bending. Without the connection to the press brake clamping system the type of the tool is important otherwise the required bend is impossible to achieve.

Standard press brake punches

Standard punches and dies

Standard punches and dies for press brake are required to perform the simple bends for the required degree according to the setup and the stroke of beam of the machine. The standard punches mean straight shape punches to make easy bends. The radius of the internal bend and the angle according to the geometry of the punch. Standard tools usually are the classic to perform the bending of boxes and simple shape parts with your press brake.

Radius press brake punches

Radius punches

If the internal radius is bigger than standard and should be obtained it is possible to use radius punches or radius inserts for punch holders with the desired radius to perform the large straight radius bending. Depends of the radius usually dies with big opening are used. Depends of the possibilities R=50 or even R=100 could be used. Press brakes with high tonnage are widely used for thick material profiles for heavy industries.
Radius punches could be also different, for example with gooseneck style to perform the bend with radius U-shape.

Gooseneck press brake punches

Gooseneck punches

To make the U-shape or channel straight punch probably can't be used because of the collisions with the part and the metal of the punch. For this purposes usually gooseneck punches are used with the shape to have the possibility not to contact with the final flange of the part (radius internal shape). Gooseneck means the special execution of the punch to have the opening at the middle for the end of part. Variety of gooseneck punches could be very big from small till big dimensions.

Gooseneck press brake special punches

Gooseneck special punches

For complicated profile shapes with closed geometry, special C-shape profiles etc. to perform the beds in U-shape and later - the last bend to close the profile, we are ready to develop and to offer special gooseneck punches according to the special geometry of your profile.
These punches are manufactured according to the geometry of the profile, possibilities and stroke of your press brake during the bending to prevent any collisions and usually to make the job with one tool even if usually it takes several different punches.

Sharp press brake punches

Sharp bends punches and dies

To perform the sharp bends usually punches and dies with the 26-28-30 degrees are used (or knife punches). The reason for the requirements of sharp bends could be different but usually it is the pre-bend (first bend) of the part to be flattened after with side to the side. Prebending with such way could be the reason of minimal deformation during the future flattening.

Hemming / flattening press brake tools
transparent bar

Hemming / Flattening tooling sets

Hemming / flattening sets are usually used to perform 26-28 degrees sharp bend and to make the flattening with the same tool thanks to the monolith special construction of punch. Flattening operation has 2 steps: primary sharp part bending and second flattening of the bendended area. This possibility has limits according to the necessary length of flattening and material thickness. Standard flattening sets in general could be used for thin metal.

Z-bend press brake tools

Z-bend press brake tools

Special press brake tools (punch and die set or offset tools) could be used for special deformations with the way of stamping, for example Z-bend in one bend. To perform the bending of this way the geometry of the shape is usually used so the way of the deoformation is other than the air bending.
The other stamping general job is to perform ribs on the sheetmetal with the use of press brake.

Main terms and glossary


Air bending - the technology of the press brake bending where the part contacts with outside edges of the die and with the end of the punch in the middle. The bend is performed by the punch which is moved with the force towards to the center of the die and usually doesn't come with the contact with the die together with the part. In general the V-opening is deeper to compensate the springback of the part after the bending. Air bending is standard and most common technology of sheetmetal bending with the press brake.

Bottom bending - the rear principle of bending where the die contacts with the part to move towards to the punch for performing of the bend. The press brake moves the die instead of punch in air bending so the contact with the parts has two points. Bottom bending could be used with rear construction of the machines with movable bottom beam of the press brake or some very special applications.

Coining or stamping - the principle of bending which is stamping in reality where the piece has the full contact with the shape of the punch and die when they are connected at the end of bend. This technology allows to get the Z-bend shape of the part, groove, rib or other special deformation. The tools are unique for the part shape and duplicates the shape of the part. Coining or stamping requires the high bending force and could be performed without the necessity of high precision.

3-points bending - special bending technology which is the special for press brakes of Bystronic-Hammerle bending machines. The technology is special because of the construction of the die and the control of the bottom part. The centered bottom position of the die is contacted with the part during the bend and controlled with the CNC. The technology declares as the best for the special and complex parts together with the highest precision of the bending.

Machine details

Bending force - declared bending force for the press brake as the max. obtained force for the bend. Bending force is calculated according to the thickness of the part, material and bend requirements.

Bending length - declared bending length as the length of the table and the max. possible length for the tooling installation. Bending length usually shows the possibility of length to be bend with the press brake. Bending length could be standard (usually declared) or inside the columns (which the same as the distance between the columns) for the parts which require the deep positioning inside the throat.

Moveable beam, trave, traverse - normally top beam of the machine which is moved together with the punch towards to the die to perform the bend. Beam has the controlled move with the hydraulic or electric systems.

Stroke of the press brake - declared stroke of the beam to move from the top position. Stroke of the bend together with the details and sizes of the punch and the die are necessary for the study of the bend possibilities.

Opening of the press brake, daylight - the max. possible distance from the top position of the beam and the bottom table without the installed tooling.

Backgauge of the press brake - backgauge is the main system at the rear part of the pressbrake wich is used as the stopper or fixation of the position of the part during the bending. Backgauge is the complex unit with the separate movements from manual to the servodrived up to 6 moveable axis with CNC control for complex parts and programs.

Crowning, deflection - press brake because the construction has the internal structure deflections during the bend which are calculated and the subject for the elimination for the precision of the bend. Depends of the construction of the press brake the compensation of such deflections could be construction integrated, handwheel manual, hydraulic with CNC control etc.

Clamping, fixation of the tool - units and systems to clamp punches and dies with the beam and the table of the press brake. There are various systems of the tool clamping and fixation depends of the model and manufacturer, machine possibilities etc. Clamping is connected with the punchholder and die holder units as the middle part of the connection. In general clamping is the manual but could be replaced with pneumatic or hydraulic units.

Tool details

Top tool or punch - top tool which is connected to the top beam of the press brake.

Die - bottom tool which is connected to the bottom table.

Punchholder - top clamping unit with the fixation elements and intermediate elements to hold the punch inside the unit.

Die holder - bottom clamping tool with fixation elements to hold the die on the table.

Angle of the tool - angle of the punch tip or die groove as desired with the tool geometry.

Radius of tool - radius of punch tip at the end or external radius of the die (two external points of the die) or the internal radius of the die (internal radius inside the groove of the die).

Groove of the die - internal groove of the die (V-opening) as the detail of the bottom tool.

Multi-V dies - special dies with the several V-openings on different sides for the universal use.

T-shape dies - T-dies as the 1-V dies with the different heights.

Height and width of the tool - external sizes of the tools.


Press brake bending tonnage and force calculator

Press brake bending tonnage and force calculator

Our online tool for quick calculation of necessary force for press brake and recommended V-die opening to execute the job.

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