Ultimate Guide to Press Brake Punches: Eleven Types, Materials, Selection, and Maintenance

1. Introduction

Looking back at history, the early press brake punches had a simple structure and could only perform basic stamping operations, but with the development of industry, modern press brake punches were gradually born. Today, punches play a vital role in the field of precision manufacturing with micron-level precision. From the initial prototype to the core object of today’s manufacturing industry, punches have witnessed and promoted the vigorous development of the manufacturing industry. Through this article, you can learn some basic knowledge about press brake punches, including what press brake punches are, the main classification of punches, what materials punches are made of, and how to choose a suitable press brake punch and the daily maintenance of punches, so that you can fully understand this very important accessory for bending.

2. What is a press brake punch?

2.1 Definition of a punch and its function in a press brake

2.1.1 Definition: Upper and lower dies of a brake press, punch: the top die of a brake press, that is, the upper die. Apply force to the metal to be bent, and bend the sheet together with the lower die.

2.1.2 Function: Apply necessary force to the metal to be processed, responsible for bending the material into a predetermined shape.

2.2 The difference and cooperation between punch and die

2.2.1 Difference: Punches generally apply bending force to the workpiece. Dies are used to fix the workpiece, support and limit the forming.

2.2.2 Cooperation: The two complement each other, one applies force and the other supports, and together complete the entire bending process.

3. Main types of punches for press brakes

3.1 Standard punching

A relatively thick body and a very thin punch, the best effect for processing thicker plates or larger pieces. It has a feature that the inner and outer sides are slightly concave and relatively flat, and can be made into a relatively short flange fold. Why is it called standard? It is because this is more common and can be used in most cases.

3.2 Acute Angle punch

This shape is very sharp and the bending angle is also small (30~60 degrees). It is very suitable for products that require a small bending angle, because the bending range is small and the quality of the finished product will be better.

3.3 Swan neck (Goose neck punch)

There is a very strange “goose neck”. This punch is “U” shaped. The “U” shape makes the U-shaped profile easier to form because it prevents the bent legs from colliding with the mold frame when bending. It is generally used for products with deeper frames or high flanges.

3.4 Curved punch

A curved shape, a curved bending design for metal sheets, which can be used in combination with some other standard punches or gooseneck punches.

3.5 Belt punch

Thin and small, used to punch holes in belts/belts.

3.6 Engagement punch (Z type)

Z-shaped tools can be used at the corners of the material. The shape characteristics can make the material form an S shape, which is the most ideal tool.

3.7 Straight punch

It can complete small angle and small size bending; it can bend 90 degrees on materials such as low carbon steel, stainless steel and aluminum, and is also the best measurement tool for testing material tensile and ductility.

3.8 Curling punch

Used for curling the edge of metal plates to enhance the structural strength of metal edges.

3.9 Radius punch

Control the radius size to achieve different curvature effects and realize different arc processing.

3.10 U-shaped punch

U-shaped punch, used to form a U-shaped groove.

3.11 Multi-V-shaped punch

Punch for processing complex parts, multiple V-shaped punches are used in rotation to reduce mold replacement.

4. Common materials and manufacturing processes of punches

4.1 Common materials (such as 42CrMo, Cr12MoV, high-speed steel, etc.)

The materials used to make punches are required to have high hardness, high toughness and wear resistance. For example, there are high-strength 42CrMo,

high-load Cr12MoV and high-speed precision high-speed steel.

4.2 Heat treatment and surface treatment methods (such as quenching, nitriding, etc.)

General punches need to be quenched to be so hard. If you want to achieve perfection, high-end products will use laser surface quenching, nitriding or welding to improve the service life and durability of the punch.

4.3 Manufacturing accuracy and its impact on the final bending quality

More accurate punches can bend workpieces with higher requirements with an error of about 0.1mm, with better bending effect and longer service life.

5. How to choose a suitable press brake punch

5.1 Material thickness

The thickness of the material determines what kind of punch to use. For example, if the material is thicker, a standard punch with large tonnage and high pressure must be used for processing, and vice versa. If it is relatively thin, it is necessary to choose a gooseneck punch or an acute-angle punch with different degrees of sophistication according to the different accuracy requirements.

5.2 Bending angle and bending radius

The bending angle and bending radius should also use different types of punches according to different needs, for example: choose a sharp angle punch for an acute angle of 30° to 60°, and choose an arc punch for a circular arc.

5.3 Compatibility with the mold

The size and shape of the upper and lower molds of the punch are consistent, which can increase synergy.

5.4 Precision and efficiency

If it is a workpiece that requires precision, the speed cannot be too slow; or if the quantity is large, consider production efficiency.

5.5 Consider wear resistance, life and maintenance cost

The press brake punch is affected by factors such as production scale and production use time. Standard punches are more durable, and other high-precision punches have a very short lifespan.

5.6 The trade-off between standard parts and customized parts

Standard punches are preferred for common processes, and customized punches are recommended for special bending scenarios.

6. Daily maintenance and care of press brake punches

6.1 Correct installation and calibration

The brake press punch is installed in a fixed slot, and the installer shall calibrate the production accuracy before commissioning.

6.2 Inspection and use process

The inspector should pay attention to observe whether the punch surface is worn, cracked, and deformed.

6.3 Cleaning, rust prevention and storage methods

After each use, the dirt should be washed away with a detergent, otherwise it is easy to get stuck and damage the punch. Anti-rust oil should be applied after use. The mold should not be exposed to moisture or chemicals, and it should be safely fixed in a metal cabinet using foam or plastic.

6.4 Recommendations on loss and replacement cycle

Determine the replacement cycle according to the actual wear and failure situation. It is recommended to replace it every shift when it is used frequently.

7. Factors affecting the performance of the brake press punch

7.1 Material thickness

In terms of material thickness, thicker materials require large bearing capacity molds, high hardness and toughness; on the contrary, thinner materials must first reach a certain precision before they can be processed and used.

7.2 Bending angle

Material angle bending is an important way to keep the deformation. Most special angles require special molds to be bent, which will not only avoid product defects, but also increase the life of the mold.

7.3 Texture direction

The texture position between different materials affects the product to a great extent. The direction along the grain will directly cause the product to crack and form defective products; while the direction against the grain increases the consumption of material energy and increases the unavoidable consumption.

7.4 Rebound effect

The effect of rebound directly determines the final bending degree and angle. Before forming, it is necessary to consider the different materials accordingly, and choose different sizes according to the punch model for production.

8. Conclusion

A good and efficient press brake punch can increase the output of the product and ensure the quality of the product. A good punch can reflect the level of a manufacturer. As the saying goes, “Excellent products attract customers.” Good punches can produce high-precision industrial products, and establishing high-quality products can produce a strong brand effect and impact, attract many customers, and gain a place in the same industry.

Here, RAYMAX suggests that if you are looking for a suitable bending press for your project, first directly contact your machine equipment supplier. Generally, they will professionally provide the corresponding type of press. You can also look for world-renowned press brake die manufacturers. This type of press product can usually fully cover your project requirements and has complete after-sales guarantees!
Of course, as a professional press brake manufacturer , RAYMAX also has a series of professional and complete press brake mold supporting equipment. If you don’t want to worry anymore, you can also directly consult us. No matter who you purchase from or not, we will provide 7* 24-hour free technical services online! As a leading enterprise in the press brake manufacturing industry, RAYMAX hopes to provide the most effective assistance to all users in the field of CNC mechanical metal manufacturing! Welcome to contact us ~