750 4 hi AGC cold rolling mill

Technical Introduction
This professionally reconditioned used 750 4 hi mill represents exceptional value in precision cold rolling, integrating advanced Secondhand AGC Cold Rolling technology within a robust 4-High configuration. Designed for high-accuracy thin-gauge production, this 4 hi precision crm delivers performance rivaling new mills at 40-60% lower capital investment. Certified for stainless steels (201/202/304), carbon steels, and non-ferrous alloys, it empowers SMEs to enter precision metal markets with minimal risk.

Core Specifications & Capabilities

Integrated AGC Hydraulic System

The cornerstone of this 4 hi precision crm's performance:

• Hydraulic Power Unit:

• Operating Pressure: 21 MPa (Max 31.5 MPa)

• Response Frequency: 15-20 Hz

• Filtration: 5μm absolute

• AGC Cylinders:

• Piston Diameter: Ø600mm

• Rod Diameter: Ø400mm

• Stroke: 100mm

• Max Thrust: 1,150 tons (dual cylinder)

• Precision Control:

• Gauge variation: ±0.5μm dynamic control

• Pressing Speed: 3.16mm/s · Reset: 3.6mm/s

Rolling Process Flow

1. Solid Winding Uncoiler → 2. Entry Roller Guide → 3. Welding Platform (stitching) → 4. Entry Hydraulic Pinch Roll → 5. Pre-Thickness Gauge → 6. Roller Guide → 7. Main 4 hi precision crm Mill Stand → 8. Hydraulic Compression System → 9. Exit Roller Guide → 10. Exit Pinch Roll → 11. Post-Thickness Gauge → 12. Welding Platform → 13. Exit Tension Roller → 14. Solid Winding Recoiler

*Integrated closed-loop AGC continuously monitors thickness at Positions 5 & 11*

Refurbishment & Certification

Reconditioning Scope:

• Work/Backup roll regrinding (Cromax® coating optional)

• AGC servo valve recalibration

• Hydraulic system rebuild with ISO VG 46 fluid

• HMI upgrade to Siemens S7-1500 PLC

• VFD motor drive modernization

Quality Assurance:

• Dimensional tolerance: ±0.005mm/m alignment

• Vibration analysis: <2.5mm/s RMS

• Load testing: 100% at 11,500 kN

• ISO 9013:2017 compliant rebuild

Technical Advantages

1. Precision Engineering

• AGC Performance: Maintains ±0.5μm strip thickness under 16.5-ton tension

• Roll Stack Rigidity: 4-Hi configuration reduces deflection by 45% vs. 2-Hi mills

• Surface Quality: Chromium-plated work rolls deliver Ra ≤0.8μm finish

2. Material Versatility

3. Operational Economics

• Power Consumption: 18 kW/ton (vs. 25+ kW/ton for older mills)

• Tooling Costs: Standard Ø180-220mm work rolls (40% cheaper than 6-Hi)

• Changeover Time: <45 minutes for alloy switching

Industry Applications

• Automotive: Fuel injector shims (0.25mm SS304 ±2μm)

• Electronics: EMI shielding cans (0.3mm cold-rolled steel)

• Construction: Architectural cladding (0.4mm patterned aluminum)

• HVAC: Precision fin stock (0.25mm copper alloy)

Refurbishment Process

How we restore peak performance to this Secondhand AGC Cold Rolling system:

1. Teardown & Inspection: Magnetic particle testing on roll chocks

2. Mechanical Rebuild:

• Roll neck bearing replacement (FAG/Optimol TF3 grease)

• Gearbox reshimming to AGMA 14 precision

3. Control System Upgrade:

• Original AGC retained with new pressure transducers

• Added Siemens S7-PLC with web inspection interface

4. Performance Validation:

• 72-hour continuous test run with SS304

• Thickness mapping: 98.7% within ±0.8μm

Value Proposition

For Whom:

• Tier 2/3 automotive suppliers

• Specialty metal service centers

• Emerging market manufacturers

Economic Benefits:

Service & Support

Pre-Commissioning:

• Material trial coordination (up to 5 tons free)

• Plant layout optimization study

Post-Purchase:

• 12-month comprehensive warranty

• Remote diagnostics via VPN connection

• Priority access to 5,000+ spare parts

• On-site technician training (Level 1-2)

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