Press Brake Punches and Dies: Key Forming Tools for Sheet Metal Bending Machines
Press brake punches and dies are special forming tools for bending machines. They are key parts for bending metal sheets, made up of two main components: upper die and lower die.
How they work: The bending machine’s slider and workbench move together, squeezing the metal sheet between the upper and lower dies.
Result: The sheet bends into the desired angle (90°, U-shape, V-shape, etc.) and size.
Uses: Widely used in mechanical manufacturing, sheet metal work, hardware production, and cabinet making.
The Critical Role of Quality Press Brake Punch and Die Sets
Press brake punches and dies work with your machine’s hydraulic power.
Even top CNC press brakes can’t fix worn, soft, or poorly ground tools.
If bends are inconsistent or tools wear out fast, check the die’s material and manufacturing.
At Alas Machinery, we offer industrial-grade bending solutions for accuracy and long use.
Metallurgy & Heat Treatment: Why 42CrMo is the Industry Standard
Most standard bending tools use carbon steel with simple surface hardening. They often bend under high pressure.
Alas Machinery uses 42CrMo and Cr12MoV alloy steels, with Full-Body Vacuum Heat Treatment. Benefits include:
Deep Hardness (47–52 HRC): Tools keep their shape after thousands of uses, no "angle drift" in finished parts.
Exceptional Toughness: Stable structure handles high-pressure bending without cracking, even for gooseneck or thin-tip punches.
Precision Grinding for Perfect Alignment
Perfect bending needs parallel tools. Our punches and dies go through high-precision CNC grinding, ensuring:
Uniform Radius: Consistent bends across the entire machine (up to 6 meters).
Modular Compatibility: Tools are ground to exact heights, so you can mix them for complex bending tasks.
Factory-Direct Spares, Ready for Immediate Use
Alas Machinery is a dedicated manufacturing facility.
We make high-performance, low-maintenance spares that are ready to install.
Our tools fit perfectly and last longer than standard ones, reducing the need for frequent adjustments.
Core Components & Basic Working Principle
Upper Die
Installed on the bending machine’s movable slider (applies pressure).
Shapes (straight, sharp, gooseneck, arc) determine the bent part’s outer look.
Lower Die
Fixed on the machine’s workbench (supports the sheet).
Has a V-groove; its width affects bending force, fillet size, and forming quality.
Working Principle
Place the metal sheet on the lower die.
The slider moves the upper die down to squeeze the sheet.
The sheet bends to match the dies’ shape (permanent deformation).
Once the preset stroke and pressure are met, the upper die moves back, and you can take the workpiece.
Characteristics of Press Brake Die
High Rigidity and Wear Resistance: Made of alloy steel (e.g., 42CrMo), heat-treated (tempered, quenched). Hardness: HRC45–HRC50. Handles high pressure and friction.
Mold Customization: Customize punches (arc, gooseneck, irregular) and dies (V-grooves of 8mm, 16mm, 24mm, etc.) based on workpiece needs.
Good Compatibility: Mold size (height, shank, installation) must match the bending machine. Forming size must match workpiece drawings.
Standardized: Conventional molds fit common machines (Amada, Trumpf, Wille) and are ready to use. Special molds can be customized.
Common Classifications of Press Brake Die
Classification by Forming Shape
Standard Straight Edge Die: For regular straight bends (most common).
Sharp Angle Die: For small angles or springback correction (high precision).
Gooseneck Die: For U-shaped and deep-channel parts (avoids bending interference).
Arc Die: For curved and rounded bends (e.g., curved workpieces).
Irregular Shaped Die: Custom-made for special workpieces (non-standard bends).
Classification by Application Scenario
Standard Sheet Metal Bending Dies: For mild steel, galvanized steel (cost-effective).
High-Strength Steel Bending Dies: Thickened, high-hardness (for stainless steel, high-strength alloy plates).
Thin Material Specific Dies: Precision-made to prevent warping, deformation, or scratching of thin sheets.
Classification by Installation Interface
Amada / Promecam Type: Fits Amada bending machines.
Trumpf / Wila Type: Fits Trumpf and Wila bending machines.
New Standard Type: Universal (fits most domestic bending machines).
Choosing the right tooling is key to accurate bends, high productivity, and long die life.
How to Select Press Brake Die
Key selection points: match material, bending process, workpiece needs, and machine parameters. Below are 5 critical tips for accurate selection (great for beginners).
1. Match Material Characteristics (Avoid Springback & Cracking)
Different metals have different springback (bounce back after bending). Choose tools that match the material’s strength and springback.
Material thickness determines die stress and forming quality. Use matching die specs for thin, medium, and thick sheets.
2. Follow the "8x Principle" (V-Notch Width Standard)
Core Formula
Lower die V-notch width (V) = 8 × material thickness (T)
Best for medium-thick sheets (3–8mm): ensures smooth bends and no cracking.
Adjustment Guidelines
Thin sheets (T＜3mm): V = 6T (smaller fillet).
Thick sheets (T＞8mm): V = 10T–12T (reduces pressure, prevents die damage).
3. Pressure Tonnage Limitation
Calculate bending pressure based on material thickness, strength, and V-notch width.
Never overload the die (causes damage).
Machine pressure must be less than the die’s rated capacity (add 10%–15% safety margin).
For thick/high-strength sheets: Use thickened or segmented dies to spread pressure.
4. Punch Shape Selection
Standard: Regular straight bends.
Sharp-angle: Small angles or springback correction.
Gooseneck: U-shaped and deep-channel parts.
Arc/custom: Circular or special-shaped workpieces.
5. Installation and Equipment Compatibility
Match the die shank to the machine’s clamping system (Amada, Trumpf/Wila, New Standard).
Die height must fit the machine’s slider stroke and table opening (avoids issues with loading/unloading).
Precautions for Selecting Press Brake Dies
Don’t ignore material springback (causes inaccurate angles).
Follow the 8x rule (prevents workpiece cracking and die damage).
Ensure compatibility with your machine (prevents installation failure).