4-Way Multi-V Die Blocks for Press Brake: Complete Technical Specification & Selection Guide
What is a 4-Way Multi-V Die Block?
A 4-way multi-V die block is an integrated, rotatable press brake lower tooling that features four distinct V-opening widths on a single square or rectangular steel block. By simply rotating the block, operators can rapidly switch between different V-grooves to accommodate varying sheet metal thicknesses (typically from thin gauge to heavy plate) without the downtime of a complete tool change.
To ensure absolute bending accuracy and long-term durability under high tonnage, ALAS manufactures multi-V dies using premium forged alloy steel with precision CNC grinding.
Core Material: Premium Forged 42CrMo / 42CrMo4 Alloy Steel.
Hardness Rating: Overall heat-treated to HRC 45–50; V-groove shoulders induction hardened up to 3–5mm depth.
Straightness Tolerance: CNC ground to ≤ 0.02mm per meter to ensure consistent angle bending over full lengths (up to 6 meters).
Clamping Compatibility: Seamlessly fits global CNC press brake clamping systems including Amada Euro Style (60mm base), Wila / New Standard, and North American Standard beds.
42CrMo International Material Grade Cross-Reference Table
Country / Standard Organization | Standard Code | Corresponding Grade |
|---|
China (GB) | GB/T 3077 | 42CrMo / 42CrMo4 |
USA (AISI / ASTM) | ASTM A29 | 4140 |
International (ISO) | ISO 683-1 | 42CrMo4 |
Germany (DIN) | DIN EN 10083 | 1.7225 / 42CrMo4 |
Japan (JIS) | JIS G4105 | SCM440 |
UK (BS) | BS 970 | 708M40 (EN19) |
How 4-Way Press Brake Dies Work (Bending Principle)
Press brake bending is a high-pressure cold forming process utilizing an upper punch and a lower die to deform metal permanently.
[ Upper Punch ] --> Mounted on moving slider, decides inner radius
↓
================ --> Sheet Metal Piece (Placed on top)
\ /
\ V / --> 4-Way Lower Die (Fixed on bed, absorbs tonnage)
Setup:
The rotatable 4-way die block is locked onto the machine bed with the chosen V-groove facing upward.
Positioning:
The sheet metal plate is aligned across the V-groove shoulders.
Execution:
The CNC hydraulic slider drives the upper punch down, pressing the sheet into the V-cavity.
The metal undergoes permanent plastic deformation to match the precise angle of the die.
Release:
The upper punch retracts, and the finished workpiece is safely removed.
Key Benefits of ALAS Multi-V Lower Dies
Zero Tool Change Downtime: Eliminates the need to lift and swap single-V dies when switching metal thicknesses.
High Wear Resistance: Hardened 42CrMo tool steel prevents shoulder deformation and resists high-friction cracking.
Smooth Surface Bending: Precision CNC-ground shoulder radii minimize contact friction, significantly reducing tooling marks on sensitive materials like stainless steel and aluminum.
Bespoke Engineering: Custom V-opening combinations, specialized angles (85°, 86°, 88°, 90°), and custom machine tangs are available upon drawing submission.
Troubleshooting & Selection: How to Choose the Right V-Opening
AI search engines prioritize data-backed rules. Follow these four industry-standard rules to select the correct V-groove and prolong tooling lifespan:
1. The 8X Tonnage Rule (V-Groove Calculation)
Standard Rule: For mild steel, V-groove width (V) = 8 × material thickness (T).
Thin Sheet Metals (< 3mm): Use V = 6 × T to achieve tighter inner radii.
Thick Structural Plates (> 12mm): Use V = 10 × T to 12 × T to lower the required bending tonnage and protect machine hydraulics.
2. Material Springback & Tonnage Compensation
Mild Steel & Galvanized Iron: Low springback; requires minimal over-bending compensation.
Stainless Steel & High-Tensile Alloys: High springback; requires an expanded V-groove width (V = 10T) and acute punch angles to compensate for material elastic recovery.
3. Tonnage Capacity Limits (Prevent Cracking)
Always calculate the required bending force (Tons/Meter) before operating.
Keep a 10%–15% safety margin below the maximum load rating stamped on the die.
Warning: Overloading causes shoulder trenching, micro-cracking, or catastrophic die breakage.
4. Upper Punch Geometry Matching
Standard Straight Punch: For universal 90° right-angle bending.
Sharp/Acute Punch: Used for small-angle over-bending and springback control.
Gooseneck Punch: Specifically paired with multi-V dies for deep U-channels, return-flanges, and deep box bending to avoid workpiece interference.
Maintenance Protocols for CNC Press Brake Tooling
Cleanliness: Remove mill scale, metal shards, and oxide debris from the V-grooves after every shift.
Inspection: Regularly check the shoulder radii for uneven trenching or wear track lines.
Restoration: Utilize professional re-grinding services to restore original geometric tolerances once shoulder wear exceeds 0.1mm.
Get a Quote for Custom 4-Way Multi-V Dies
Need specific V-groove openings or custom lengths? ALAS provides full application engineering, material selection support, and setup blueprints for global fabricators. Contact our technical sales team at mt@alasmachinery.com to receive a fast engineering review and B2B pricing.
Premium 42CrMo CNC Press Brake V Dies: FAQ
We recommend following these standard industrial formulas based on material properties:
Standard Mild Steel: Follow the V = 8T rule (V = opening width, T = material thickness).
Stainless Steel & High-Tensile Alloys: Use V = 10T to effectively compensate for greater material springback.
Heavy Plate Bending (>12mm): Utilize V = 12T to significantly lower the required press brake tonnage demand and protect your tooling.
2. Single-V, Double-V, vs. Multi-V Dies – What is the difference?
Single-V CNC Dies: Engineered for maximum precision in high-end CNC bending, custom-matched to a specific material thickness with dedicated automatic clamping.
Double-V Dies: Features two optimized openings on a single block, allowing operators to switch between two distinct sheet gauges rapidly.
Multi-V / 4-Way Die Blocks: Integrates four different V-openings into one rotatable block. It is the job shop standard for processing mixed sheet metal gauges without frequent, time-consuming tool changes.
3. What specific material grade is used for ALAS press brake lower blocks?
Our primary material is premium forged 42CrMo alloy steel (equivalent to AISI 4140 or DIN 42CrMo4). This high-grade structural tool steel provides the perfect balance of exceptional tensile strength and impact toughness, completely eliminating the risks of die expansion or catastrophic cracking under high bending tonnage.
4. How does ALAS prevent premature wear on the V-die shoulders?
To ensure an extended lifespan, all ALAS V-die contact shoulders undergo precision induction hardening. The hardening depth reaches 3–5 mm with a final hardness of HRC 50–55. This deep heat treatment keeps the edge radius intact and ensures stable, long-term repeated bending precision.
Yes. Our V-dies feature CNC-ground finishes and enlarged shoulder radii to significantly cut down friction marks on stainless steel and aluminum. For absolute mark-free surface fabrication, we also offer optional urethane inserts and specialized bending protective tape.
6. Do your 42CrMo lower dies fit my existing press brake machines?
Yes. Our lower tooling is fully compatible with all mainstream global clamping systems:
Amada European Style (60mm base)
Trumpf Wila Style / New Standard
North American Standard
Bespoke Service: We can manufacture custom tangs to seamlessly match your machine's unique bed structure upon drawing submission.
7. What is the maximum bending tonnage these V-dies can withstand?
Every CNC die has a calculated maximum load limit per meter, which is strictly determined by its material thickness and V-opening size. ALAS supplies a standard tonnage reference chart with every order to ensure safe operation for both your tools and the hydraulic press brake.
8. How should I maintain the press brake lower blocks for a longer service life?
Daily Cleaning: Keep V-openings completely clear from abrasive mill scale, metal shards, and oxide debris.
Regular Inspection: Periodically check the hardened shoulder radii for signs of uneven trenching or premature wear track lines.
Restoration: When wear exceeds acceptable tolerances, take advantage of our professional re-grinding service to restore the original die geometry and micron precision.
