1. Overview of Cold Shear Machine

A Cold Shear Machine is a type of industrial cutting equipment used to cut metal billets, bars, plates, or rolled products at room temperature, hence the name “cold” shear.
Unlike hot shears, which operate at high temperatures during rolling, cold shears are mainly used after cooling or in post-rolling processes, where materials have solidified and require high precision in dimensional control.

The cold shear is commonly installed at the end of rolling lines, cut-to-length systems, or steel bar processing workshops.
It can perform fixed-length cutting, sample shearing, tail cutting, and defect removal with high accuracy and reliability.
Modern cold shear machines are equipped with hydraulic or mechanical drives, PLC automatic control, and servo synchronization systems, enabling automatic operation, stable performance, and consistent precision.

2. Working Principle

The Cold Shear Machine works by applying a powerful shearing force through upper and lower blades, driven by a mechanical crank, flywheel, or hydraulic cylinder.
When the billet or steel bar reaches the preset cutting length, the control system sends a signal to trigger the cutting action.
The upper blade moves downward to cut the material against the stationary lower blade, achieving a clean and accurate cut.

The working sequence includes:

1. Material Feeding:
   The steel bar or plate is fed into the shear through a Roller Conveyor or guide mechanism.

2. Length Measurement:
   A length encoder continuously measures the running length.

3. Signal Processing:
   The control system (PLC) calculates when to activate the shear based on target length and line speed.

4. Shearing Action:
   The drive system (mechanical or hydraulic) moves the blade to cut the material.

5. Discharge:
   The cut section is transferred to a stacking or bundling area automatically.

In modern high-speed production lines, cold shears can operate continuously with precise timing, ensuring synchronized cutting with the moving material.

3. Structural Components

A typical Cold Shear Machine consists of the following major components:

1. Frame Structure:
   Heavy-duty welded steel base ensuring rigidity and vibration resistance.

2. Upper and Lower Blades:
   Made of wear-resistant alloy steel; blades are replaceable and adjustable.

3. Driving Mechanism:
   Can be mechanical (crank and flywheel) or hydraulic, depending on design.

4. Clutch and Brake System:
   Engages and disengages motion at precise intervals for cutting.

5. Length Measuring Device:
   Encoder or laser sensor for precise measurement of material length.

6. Transmission System:
   Transfers power from the motor to the crankshaft or hydraulic pump.

7. Hydraulic System (if equipped):
   Includes pump station, valves, and cylinders to drive blade movement.

8. Control Cabinet (PLC):
   Central control unit for automatic timing and monitoring.

9. Lubrication System:
   Ensures smooth motion and prevents wear.

10. Safety Guarding:
    Protective covers and emergency stops for operator safety.

4. Technical Features and Advantages

1. High Cutting Precision:
   Length accuracy within ±1 mm.

2. Strong Shearing Force:
   Suitable for cutting billets up to 400 mm in diameter.

3. High Efficiency:
   Capable of 60–120 cuts per minute depending on material and drive system.

4. Automation:
   Integrated PLC control for fully automatic operation.

5. Low Noise and Vibration:
   Optimized dynamic balance and damping structure.

6. Durability:
   Alloy blades and robust frame ensure long service life.

7. Easy Maintenance:
   Modular structure allows convenient part replacement.

8. Adaptability:
   Adjustable cutting frequency and stroke for different materials.

5. Control System

The control system is the “brain” of the cold shear machine.
It typically includes:

• PLC (Programmable Logic Controller): Handles logic and timing.

• HMI (Human–Machine Interface): Displays operation data and alarms.

• Encoder: Measures material length in real time.

• Servo Control Unit: Adjusts shear timing to match line speed.

• Interlock and Safety Circuits: Ensure safe and coordinated operation.

Advanced models use closed-loop control, where real-time feedback ensures each cut matches the preset length even during speed variations.

6. Applications

• Steel Rolling Lines:
  Cutting billets, rods, or bars at room temperature.

• Continuous Casting Plants:
  Cutting cooled billets after the cooling bed.

• Metal Plate Processing:
  Cutting steel sheets into fixed lengths for automotive, shipbuilding, or construction use.

• Pipe and Tube Production:
  Cutting pipe sections before forming or packaging.

• Rebar and Wire Rod Plants:
  Shearing finished bars into standard commercial lengths.

7. Maintenance and Safety

1. Regularly inspect the blade condition and sharpen or replace as necessary.

2. Check oil levels and cleanliness in hydraulic systems.

3. Inspect bearing lubrication and alignment.

4. Test clutch, brake, and safety interlocks monthly.

5. Keep sensors and encoders clean and calibrated.

6. Never exceed the rated cutting capacity.

Conclusion

The Cold Shear Machine plays a vital role in the modern steel and metal processing industry.
It combines mechanical precision, automation, and durability, offering a reliable solution for cutting cooled billets, bars, and plates with high accuracy and efficiency.
With the continuous advancement of servo, hydraulic, and digital control technologies,
cold shears are evolving toward higher speed, better energy efficiency, and smarter operation,
making them indispensable in the future of intelligent steel production.