The 174mm R4 Lower Bending Blade is a precision long-format tool designed for flexible panel benders and CNC panel bending centers. Installed in the lower bending position, it approaches the projecting sheet flange from below and follows the programmed machine trajectory to produce controlled upward bends.

This panel bender lower blade has an overall height of 174 mm and a maximum width of 40 mm. The lower working section narrows to 25 mm and incorporates an offset profile that creates additional clearance around the bending zone. Its precision-machined R4 working edge provides smooth and stable contact with the underside of the sheet during forming.

With a continuous length of 1400 mm, the blade is suitable for processing longer panels, doors, cabinets, enclosures and industrial sheet metal components. Accurate straightness, parallelism and working-edge consistency are particularly important for maintaining uniform bending performance across this extended tool length.

The complete blade is manufactured from 42CrMo alloy steel, overall quenched and through-hardened to HRC46–52. This combination provides a reliable balance of structural strength, toughness, dimensional stability and resistance to repeated working-edge contact.

WYS Machinery can manufacture standard and customized lower bending blades according to original tooling drawings, machine-interface dimensions, physical samples or customer workpiece requirements.

Key Features

Precision lower bending blade for flexible panel benders
Overall tool height of 174 mm
Maximum tool width of 40 mm
Reduced lower section width of 25 mm
Precision-machined R4 working radius
Long continuous tool length of 1400 mm
Designed for controlled upward sheet metal bending
Offset working profile provides clearance around the bending zone
Manufactured from 42CrMo alloy steel
Overall quenched and through-hardened
Finished hardness of HRC46–52
Multiple mounting holes provide secure installation and alignment
Suitable for long panels and extended bending lines
Available as replacement or custom panel bender tooling
Custom lengths, profiles, radii and hole patterns available

Technical Specifications

Specification	Value
Product Type	Lower Bending Blade
Tooling Category	Panel Bender Tooling
Application	Flexible Panel Bender / CNC Panel Bending Center
Overall Height	174 mm
Maximum Tool Width	40 mm
Reduced Section Width	25 mm
Working Radius	R4
Standard Length	1400 mm
Material	42CrMo Alloy Steel
Heat Treatment	Overall Quenching / Through-Hardening
Hardness	HRC46–52
Installation Position	Lower Bending Position
Typical Bending Direction	Upward Bending
Mounting Method	Multiple Mounting Holes
Construction	Long Continuous Blade
Custom Dimensions	Available
Custom Mounting Interface	Available
Machine Compatibility	According to Confirmed Interface Dimensions

Function and Working Principle

During a typical panel bending cycle, the sheet metal is positioned between the upper blankholder and fixed counterblade. The blankholder secures the material against the counterblade and establishes the programmed bending line.

The lower bending blade then approaches the projecting flange from below. Instead of moving only vertically like conventional press brake tooling, it follows a CNC-controlled trajectory around the clamped edge of the sheet. This movement lifts and forms the flange to the required angle.

The lower blade works together with the other core panel bender tools:

Tooling Component	Main Function
Blankholder Tool	Clamps and positions the sheet from above
Counterblade	Provides fixed lower support and bending reference
Upper Bending Blade	Produces controlled downward bends
Lower Bending Blade	Produces controlled upward bends
Special Panel Bender Tools	Support special clearance and forming requirements

The coordinated use of upper and lower bending blades allows positive and negative bends to be produced without repeatedly turning the entire panel.

Difference Between a Lower Bending Blade and Counterblade

Although both components are positioned below or close to the sheet, they perform different functions.

The counterblade remains the fixed lower support that works with the blankholder to secure the sheet. The lower bending blade is the moving working tool that contacts the projecting flange from below and performs the upward bending movement.

Using accurate product terminology helps customers distinguish between:

Lower bending blades
Counterblades
Lower support tools
Blankholder tools
Conventional press brake lower dies

A lower panel bender blade should not be described as a V-die because it does not use a conventional V-opening to form the sheet.

R4 Working Radius

The R4 rounded working edge provides a broader and smoother contact profile than a smaller-radius blade. As the blade follows its programmed trajectory, the R4 edge transfers forming force to the underside of the sheet.

The R4 profile can help provide:

Smooth engagement with the sheet
Controlled contact during upward bending
Reduced concentration of pressure at the working edge
Stable force transmission along the bending line
Consistent operation over the 1400 mm length
Suitability for applications requiring a larger blade radius

The final workpiece radius is also influenced by sheet thickness, material properties, clamping position, blade path and machine settings. An R4 tool edge does not automatically guarantee an R4 finished internal radius.

Alternative working radii can be produced according to customer drawings and actual forming requirements.

Offset Lower Working Profile

The lower section narrows to 25 mm and bends outward toward the R4 working edge. This offset geometry positions the working radius correctly beneath the sheet while providing clearance between the blade body and surrounding workpiece geometry.

The offset profile can help:

Reduce interference near the forming area
Provide clearance for the projecting flange
Accommodate the programmed lower-blade trajectory
Improve access around partially formed panels
Support the production of cabinets and box-shaped components
Maintain structural strength through the 40 mm upper body

WYS can customize the lower profile when the machine installation or finished component requires different clearance.

1400mm Long Continuous Blade

The 1400 mm continuous length supports long bending lines and larger sheet metal components. A one-piece blade eliminates intermediate joints across the working length and provides a continuous R4 contact edge.

Important quality requirements for a long lower bending blade include:

Consistent overall height
Accurate straightness
Uniform R4 edge geometry
Parallel mounting surfaces
Correct mounting-hole positions
Controlled heat-treatment deformation
Reliable machine alignment

Alternative continuous lengths, matched sections and segmented blade sets can be supplied according to the machine configuration.

42CrMo Material and Heat Treatment

This lower bending blade is manufactured from 42CrMo alloy steel, selected for its strength, toughness and resistance to repeated mechanical loading.

The complete tool undergoes overall quenching and through-hardening to HRC46–52. Controlled heat treatment helps provide:

Consistent hardness throughout the tool body
Reliable resistance to repeated bending loads
Improved working-edge wear resistance
Stable mounting and working geometry
Resistance to unwanted deformation
A suitable balance between hardness and toughness

Heat-treatment control is particularly important for the 1400 mm continuous construction because excessive distortion could affect straightness and working-edge alignment.

Typical Applications

This R4 lower bending blade can support the production of:

Electrical cabinets and control enclosures
Long switchgear panels
Elevator doors and interior panels
Metal doors and frames
HVAC and ventilation panels
Server and communication cabinets
Industrial equipment covers
Storage cabinets and shelving
Stainless steel kitchen equipment
Appliance panels and housings
Lighting enclosures
Metal furniture components
Long box-shaped sheet metal parts
Multi-sided panels
Precision sheet metal enclosures
Custom industrial panels and profiles

Actual forming capability depends on the panel bender model, sheet material, material thickness, flange geometry, tooling configuration and programmed blade trajectory.

Product Details and Manufacturing Quality

Each lower bending blade can be manufactured according to an original technical drawing, physical sample or confirmed machine-interface data.

The manufacturing and inspection process may include:

42CrMo raw-material verification
CNC profile machining
Precision mounting-hole machining
Controlled overall quenching
Through-hardening
Precision machining after heat treatment
R4 working-radius inspection
Overall height and width verification
Reduced-section inspection
Mounting-hole position verification
Straightness inspection
Parallelism inspection
Working-edge consistency inspection
Final dimensional and visual inspection

For a continuous 1400 mm blade, straightness and uniform working-edge geometry receive particular attention during production and final inspection.

Replacement Lower Bending Blades

This product can be supplied as a replacement lower blade for flexible panel benders and automated sheet metal bending centers with a corresponding mounting interface.

To confirm machine compatibility, customers should provide:

Machine brand and model
Original lower blade drawing
Machine-interface drawing
Existing tooling dimensions
Mounting-hole pattern
Physical tooling sample
Installation photographs
Required working length
Finished workpiece drawing

Compatibility should be determined from the actual blade profile and interface dimensions rather than assumed from the machine brand alone.

Standard and Custom Panel Bender Tooling

WYS Machinery manufactures complete tooling solutions for flexible panel benders and CNC panel bending centers, including:

Blankholder tools
Counterblades
Upper bending blades
Lower bending blades
Long continuous bending blades
Matched upper and lower blade sets
Segmented panel bender tools
Special panel bender tooling
Custom replacement tools

Available customization options include:

Overall blade height
Maximum width
Reduced-section width
Working radius
Offset working profile
Continuous tool length
Segmented construction
Mounting-hole quantity and position
Machine installation interface
Heat-treatment requirements
Surface treatment
Special clearance geometry

Customers can provide original tooling drawings, physical samples or finished sheet metal component drawings. WYS offers free tooling evaluation and design support to develop an appropriate panel bending solution.

Matched Upper and Lower R4 Blade Set

This lower blade can work as part of a matched tooling combination with the corresponding 174mm R4 Upper Bending Blade.

Using coordinated upper and lower blade profiles helps establish a complete tooling solution for:

Upward and downward bending
Long panel production
Positive and negative flange forming
Extended 1400 mm bending lines
Replacement of worn upper and lower tools
Customized flexible panel bender applications

Mounting interfaces, working positions and blade trajectories should be confirmed before producing a matched set.

Why Choose WYS Panel Bender Tooling

Panel bender tools manufactured from drawings or samples
42CrMo alloy steel construction
Controlled overall quenching and through-hardening
Precision-machined R4 working edge
Experience manufacturing long continuous blades
Custom hole patterns and machine interfaces
Continuous and segmented tool options
Matched upper and lower bending blade sets
Free tooling evaluation and design support
Dimensional inspection before delivery
Protective packaging for long industrial tooling

Frequently Asked Questions

What is a lower bending blade on a panel bender?

A lower bending blade is the moving tool installed in the lower bending position. It contacts the projecting sheet flange from below and follows a programmed trajectory to perform an upward bend.

Is a lower bending blade the same as a counterblade?

No. The counterblade provides fixed lower support. The lower bending blade moves against the sheet to perform the forming operation.

Is this product a press brake lower die?

No. A press brake lower die normally uses a V-opening. A panel bender lower blade follows a controlled trajectory around the sheet edge.

What is the working radius of this blade?

This model has an R4 working edge. Other radii can be manufactured according to customer drawings and forming requirements.

Does an R4 blade always produce an R4 finished bend radius?

No. The final radius also depends on the sheet material, thickness, clamping position, machine program and blade trajectory.

What is the advantage of the 1400 mm continuous length?

It provides an uninterrupted working edge for long bending lines and larger sheet metal panels.

Can this lower blade be matched with an upper blade?

Yes. It can form a matched tooling set with the corresponding 174 mm high, 1400 mm long R4 upper bending blade, subject to confirmation of the machine interface.

What material and hardness are used?

The blade is manufactured from 42CrMo alloy steel, overall quenched and through-hardened to HRC46–52.

Can the blade dimensions and mounting holes be customized?

Yes. Height, width, profile, working radius, length, mounting holes and machine interface can be customized.

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