Complete Guide to Press Brake Dies: Types, Materials and Applications

A press brake die is one of the most important components in the bending process. While the machine provides the bending force, the die determines how the sheet is supported and formed.

Choosing the right press brake die can affect bending accuracy, inside radius, surface quality, tooling life and production efficiency.

In this guide, we explain four common types of press brake dies and how to select the right one for different applications.

1. What Is a Press Brake Die?

A press brake die is the lower tooling installed on the press brake table. It works together with the upper punch to form the sheet metal into the required angle and shape.

The main factors affected by the die include:

• Bending angle

• Inside bend radius

• Required bending force

• Surface marking

• Tool life

• Bending consistency

The most suitable die depends on the material, thickness, bending method and final part geometry.

2. V Die

The Most Common Press Brake Die

The V die is the most widely used lower tooling for press brakes. It is particularly common for air bending and general sheet metal fabrication.

Typical applications include:

• Mild steel

• Stainless steel

• Aluminum

• Electrical cabinets

• HVAC components

• Machine parts

• General fabrication

V Die Opening

The V opening is an important factor when selecting a die.

As a general starting point for air bending, the V opening is often around 6–8 times the material thickness. However, the actual selection also depends on material strength, inside radius, bending length and machine capacity.

A suitable V opening helps balance:

Bending force + bend radius + surface quality + tooling stability

3. U Die

For Special Forming Applications

A U die uses a U-shaped or specially designed cavity instead of a conventional V opening.

It is generally used when a standard V die cannot provide the required forming geometry.

Typical applications include:

• Channel-shaped parts

• Deep forming

• Special profiles

• Customized bending applications

U dies are often designed according to the actual workpiece drawing, making them particularly useful for customized tooling projects.

4. Radius Die

For Controlled Large-Radius Bending

A radius die is designed for applications requiring a larger or specific inside bending radius.

It can be useful when standard V tooling cannot achieve the required bend profile efficiently.

Typical applications include:

• Stainless steel parts

• Aluminum components

• Architectural panels

• Automotive parts

• Decorative sheet metal

A suitable radius die can improve radius consistency and reduce unwanted surface damage.

5. Hemming Die

For Folding and Flattening Sheet Edges

A hemming die is used to fold a sheet edge back onto itself.

Hemming normally involves two steps:

Pre-bending → Flattening

This creates a closed or reinforced edge.

Common applications include:

• Automotive parts

• Electrical enclosures

• HVAC components

• Metal furniture

• Sheet metal housings

Hemming improves edge safety, rigidity and appearance.

6. V Die vs U Die vs Radius Die vs Hemming Die

The four die types are designed for different forming requirements. Choosing the right one starts with the workpiece rather than simply the press brake model.

7. How to Choose the Right Press Brake Die

Before selecting a die, consider the following factors.

Material Thickness

Thicker materials generally require a larger V opening and higher bending force.

Material Type

Mild steel, stainless steel and aluminum have different bending characteristics and surface requirements.

Inside Bend Radius

The required radius determines whether a standard V die or specialized radius tooling is more suitable.

Bending Method

Air bending, bottom bending and coining may require different tooling configurations.

Machine Compatibility

Check the:

• Press brake model

• Tooling interface

• Die height

• Die length

• Clamping system

Surface Quality

For stainless steel, aluminum and decorative parts, low-marking or radius tooling may be a better choice.

8. Press Brake Die Materials

The material and heat treatment of a die directly affect its hardness, wear resistance and service life.

42CrMo

Known for good strength and toughness. It is suitable for heavy-duty and thick-plate bending applications.

Cr12MoV

A commonly used tool steel offering high hardness and good wear resistance for general press brake tooling.

SKD11

A premium tool steel option with excellent hardness, wear resistance and dimensional stability for demanding applications.

The best material depends on the working conditions rather than simply choosing the hardest steel.

9. Standard or Custom Press Brake Dies?

Standard dies are suitable for most common bending operations.

However, custom dies are recommended when you need:

• Special bending radius

• Deep channels

• Narrow flanges

• Special profiles

• Long continuous bends

• Reduced surface marking

When ordering custom tooling, provide the manufacturer with the part drawing, material, thickness, bending angle, inside radius and bending length.

This allows the tooling manufacturer to design the die around the actual application.

10. Press Brake Die Maintenance

Proper maintenance helps extend tooling life and maintain bending accuracy.

Clean the dies regularly

Remove metal particles, oil and other contaminants.

Check for wear

Inspect the die shoulders for scratches, deformation, chipping and excessive wear.

Protect against rust

Apply suitable anti-rust protection during long-term storage.

Store correctly

Keep tooling in a clean and dry environment and use a dedicated tooling rack where possible.

Check alignment

Incorrect installation can cause uneven loading and accelerate tooling wear.

11. When Should You Replace a Press Brake Die?

A die should be replaced when wear starts to affect bending quality.

Common warning signs include:

• Uneven bending angles

• Visible damage

• Excessive shoulder wear

• Repeated surface marks

• Dimensional inconsistency

• Tool deformation

Replacing worn tooling at the right time can help prevent production defects and unnecessary downtime.

Conclusion

Choosing the right press brake die is essential for accurate and consistent sheet metal bending.

For general bending, the V die is the most versatile option. For special profiles, a U die may be more suitable. A radius die is designed for controlled large-radius bending, while a hemming die is used for folding and flattening sheet edges.

The best tooling choice should always consider:

Material + Thickness + Bend Radius + Bending Method + Machine Compatibility

With the right die material, accurate manufacturing and proper maintenance, press brake tooling can provide reliable performance and a longer service life.