CNC press brakes are indispensable tools in the metal fabrication industry, enabling precise bending and shaping of various metals with high accuracy. Whether you’re using a classic hydraulic press brake or an advanced CNC hydraulic model, selecting the right metal is critical for achieving clean, repeatable results. In this guide, we’ll cover the most common metals that CNC press brakes can process and what to consider for each material.

1. Mild Steel (Carbon Steel)

Mild steel is one of the most commonly bent materials on CNC press brakes due to its affordability, formability, and excellent strength properties.

Why it’s suitable:

• Good ductility for easier bending
• Versatile thickness range
• Strong structural integrity

Typical Applications:

• Construction materials
• Machinery components
• Automotive parts
• Electrical cabinets

Whether working with thin sheets or thicker plates, CNC press brakes can handle mild steel efficiently, ensuring consistent results.

2. Stainless Steel

Stainless steel is known for its corrosion resistance and strength. However, due to its higher springback and strength, it requires more force to bend, making CNC hydraulic press brakes the ideal tool for this material.

Popular Grades: 304, 316, 201
Key Characteristics:

• Higher tonnage requirement
• More springback compared to mild steel
• Needs a specific punch radius

Common Uses:

• Food-grade equipment
• Medical device housings
• Decorative steel panels
• Architectural features for outdoor use

Given its resistance to corrosion and high strength, stainless steel is a popular choice for demanding applications, though it needs extra care in bending.

3. Aluminum

Aluminum is lightweight, corrosion-resistant, and relatively easy to bend, making it an ideal material for industries that prioritize both strength and weight reduction.

Suitable Grades: 5052, 6061
Bending Behavior:

• Softer alloys bend easily
• Harder grades may crack if not handled properly
• Requires attention to the inside radius during bending

Typical Applications:

• Aerospace components
• Electronics enclosures
• Transportation parts
• Decorative panels

CNC press brakes offer precision and clean bends for aluminum, minimizing marking when used with the appropriate tooling.

4. Copper and Brass

Copper and brass are highly ductile, soft metals that bend smoothly even at tight radii. These metals require lower bending forces and deliver excellent surface results.

Applications:

• Electrical components
• Decorative panels
• HVAC systems
• Precision instrument parts

These materials bend with ease on a CNC press brake, offering minimal risk of cracking, making them perfect for delicate, high-quality fabrications.

5. Galvanized Steel

Galvanized steel behaves similarly to mild steel but features a protective zinc coating. When bending galvanized steel, it’s essential to avoid damaging the coating, as it can reduce the material’s protective properties.

Common Applications:

• Ductwork
• Structural parts
• Outdoor cabinets
• Building materials

The right die selection is crucial for maintaining the integrity of the zinc coating during the bending process.

6. Titanium and Specialty Alloys

Titanium, high-strength steels, spring steel, and other specialty alloys are also bendable with CNC press brakes. However, they require significantly higher tonnage and more precision due to their higher strength and springback.

Why CNC Press Brakes are Necessary:

• High tonnage for bending high-strength alloys
• Programmable angle control for precise adjustments
• Springback compensation for accurate bends

Industries Using These Metals:

• Aerospace
• Defense
• Medical devices
• High-performance machinery

CNC hydraulic press brakes are particularly useful for bending these challenging materials, offering both stability and accuracy.

7. Material Thickness & Grade Limitations

The bendability of metal depends on various material properties, such as:

• Tensile strength
• Thickness
• Grain direction
• Ductility
• Hardness

Choosing the correct press brake tonnage and die width is essential for processing each material. Most CNC press brakes come with tonnage calculators and bending charts to ensure proper setup.

8. Factors Influencing Metal Bendability

Achieving precise and repeatable bends requires understanding several key factors:

• Springback (particularly with stainless steel and aluminum)
• Bend radius and tooling selection
• Rolling direction (grain direction can affect cracking)
• Machine tonnage capacity
• Material hardness

CNC systems automatically adjust for springback, which makes the bending process more accurate and consistent.

Conclusion

CNC press brakes are incredibly versatile machines that can bend a wide range of metals, from mild steel and aluminum to titanium and high-strength alloys. With the precision and flexibility provided by CNC technology, these machines deliver consistent results for both simple and complex fabrication tasks. Proper tooling, machine settings, and a good understanding of the material’s properties are essential for achieving high-quality bends and optimal results in metal fabrication.