Types Of Sheet Metal Bending
Those who work in sheet metal fabrication know that shaping metal, even on an industrial scale, is...
Press brake tooling consists of punches and dies that are used to shape sheet metal into desired forms. The punch is the top tool that presses down on the material, while the die is the bottom tool that supports the material during the bending process.
What is a press brake?
A press brake is a machine used to bend sheet metal into various shapes. It consists of a top beam (punch) that moves vertically and a bottom beam (die) that remains stationary. The sheet metal is placed between the two beams, and the punch is pressed down to bend the material. There are several types of press brakes: mechanical press brakes, hydraulic press brakes, hybrid press brakes, CNC press brakes, Rotary press brakes. Read our comprehensive guide which explains each type of press brake.
Choosing the Right Press Brake Tooling
Selecting the appropriate tooling for your press brake is crucial for achieving accurate and efficient results. Here are some key factors to consider:
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Material Type: the thickness, strength, and ductility of the material will determine the best tooling options.
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Bend Angle: the desired bend angle will influence the choice of punch and die shapes.
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Bend Radius: the radius of the bend will impact the tooling requirements.
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Tooling Configuration: consider factors like V-die openings, punch profiles, and tooling materials.
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Press Brake Capacity: ensure your tooling is compatible with the tonnage capacity of your press brake.
What material is used for press brake tooling?
Press brake tooling is typically made from hardened tool steels or carbide materials. These materials offer excellent wear resistance, durability, and heat resistance, making them suitable for demanding bending applications.
Setting Up Press Brake Tooling
Proper setup of press brake tooling is essential for accurate and safe operation. Follow these general guidelines:
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Cleanliness: ensure the tooling and press brake bed are clean to prevent scratches and debris from affecting the bending process.
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Alignment: carefully align the punch and die to ensure proper contact with the material.
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Clamping: secure the tooling in place using the appropriate clamping mechanisms.
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Tonnage Adjustment: set the press brake tonnage to match the requirements of the material and bend.
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Safety Checks: conduct safety checks before operating the press brake to ensure proper setup and prevent accidents.
Additional Consideration
It is important to carry out a correct tool maintenance: regular maintenance, including cleaning, lubrication, and inspection, is essential for prolonging tool life and ensuring optimal performance. If your are interested in the topics, we have created a guideline for proper maintenance of the press brake.
Top Tooling Types: Punches
Punches are tools fixed to the ram by various fastening systems. Punches are essentially the blades that descend from above onto the sheet metal during bending, tracing the bend line and thus determining the subsequent height of the flange.
They can be classified based on their characteristics, which will then tell us whether or not a tool is suitable for performing a bend. The mechanical and dimensional characteristics are always found in the catalog and are often stamped on the front of the punch.
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Product code: the name assigned by the manufacturer; it consists of a series of numbers that provide mechanical and dimensional information about the punch.
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Degrees: the inclination between the faces immediately adjacent to the tip radius. Visually, they already show whether a punch is designed to be able to make bends closer than 90°. Among the most common are those at 90° (specific for coining), 88° (excellent for deep drawing), 85°, 60°, 35°, 30°. These last ones are often called needle tools to emphasize their very pointed shape. They are used for common air bends and for performing the bend-squeeze operation.
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Height: the useful height which in the European standard is equal to the total height minus the 30 mm of the attachment to the intermediate. Tools with a greater height allow for good use in the creation of deep boxes.
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Radius: the radius of the punch tip and visually shows us what type of use it was designed for. Generally, a larger radius suggests use for thicker materials or for bending thin sheet metal but with very large-radius bends. Some tools have a flat tip and have specific uses, for example, if the flat vertex segment is quite long, in hemmed bends (calendering) of large thicknesses.
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Load: the maximum bending force that the punches can be subjected to, the limit beyond which the risk of irreversible deformations or breakage begins. Those known as swan neck, mostly suitable for tight and consecutive bends, can rarely have maximum loads comparable to those of straight tools, for a simple geometric reason.
How to select a punch for your press brake
There are many types of punches available for different jobs. The punch selection should be made only after knowing the basics of each type of press brake punches. These different punches are:
Standard Punch
The standard punch is the most common press brake tool. Its thick body and narrow tip generate high tonnage, suitable for bending thicker materials. The inward side has a slight concave curve with flat outsides, allowing for shorter flange folding.
Acute Angle Punch
Use acute angle punches for very short bends, typically 30° or less. They can also handle larger angles like 60°. These punches have a sharp tip and a generally bulky body.
Narrow Punch
Narrow punches are uniformly thin throughout. They fit in tight spaces where other punches might not. They're also known as sword punches. A common application is closing square or box profiles.
Sash Punch
Sash punches have a narrow body and an angled tip that bends inward. They're ideal for creating bends around corners, like door jambs and sashes.
Swan Neck Punch
Swan neck punches are used for marking applications and creating U-shaped profiles. Their unique shape prevents workpiece legs from colliding with the tooling. Gooseneck punches are similar but weaker due to the unsupported line of force.
Joggle Punch
Joggle punches are specialized tools for making bends around corners. Their thinner profile is ideal for creating S-shaped bends. They're less common and used for niche applications.
Radius Top Punch
Radius top punches have a rounded tip instead of a sharp one. This creates a U-shaped bend instead of a sharp V-shape. They're often used with a U-shaped die for rounded corners.
Bottom Tooling Types: Dies
Dies are the lower tools attached to the press brake table. They come in various shapes and sizes, but most have a V-shaped opening. Common V-opening angles range from 90° (for coining) to 30°.
Multiple dies offer versatility, allowing you to bend different thicknesses without changing tools. However, they can be limited in height, especially for Z-shaped pieces with tight bends.
T-dies are another option. They have a single V-opening but offer more flexibility in terms of dimensions. With a bit of experience, you can visually assess the suitability of a die for a particular bending application.
Dies can be classified based on:
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Product code: a unique identifier for each die, assigned by the manufacturer.
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Degrees: the angle of the V-shaped opening in the die, determining the maximum bend angle.
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Radius: the radius of the rounded corners of the V, affecting the quality of the bend.
Single V Die
A single V die features a V-shaped cavity. They're the most common press brake die due to their versatility. The V-die opening should ideally be eight times the material thickness.
Two-Way Self-Centering V Dies
These dies have two parallel V-shaped cavities, streamlining the bending process. You can change bend angles without retooling.
Multi V Die
Multi V dies have multiple V cavities, offering various bending options. Rotating the die allows you to change bend angles or material thickness.
Corrugating Dies
Corrugating dies create a corrugated pattern on the sheet metal. They're used for specific applications requiring a textured surface.
Flattening & Hemming Dies
These dies fold and flatten the entire flange length in an acute angle bend. They come in sprung-loaded and U-section styles.
Channel Forming Dies
Channel forming dies create a U-shaped channel in one pass, instead of the traditional two-pass process using V dies.
Tool clamping systems
When selecting press brake tooling, it's essential to consider the clamping system. The clamping system significantly affects machine setup time. We've summarized 7 tips to optimize your press brake setup.
Clamping System Types
Tool clamping systems can be classified by their attachment type, like Promecam (European) or WILA. Upper and lower tool clamps can also vary by fastening technology: manual, semi-automatic, hydraulic, or pneumatic.
Press brake tool storage
Loading and unloading press brake tools is time-consuming. VICLA's automatic tool changer reduces setup time by up to five times. Learn all about automatic tool changers: what they are, how they work, and their benefits.
