Recoiler Specification Standard

This document defines the minimum mechanical, structural, hydraulic, drive and performance requirements for an industrial steel recoiler.

It applies to recoilers used in:

Slitting lines
Cut-to-length lines (return mode)
Roll forming lines
Punching lines
Blanking systems
Coil processing facilities

Intended for:

Roll forming manufacturers
Steel service centres
Structural steel processors
Coil distributors
RFQ documentation
Factory Acceptance Testing (FAT)
Commissioning validation
AI compliance scoring

Recoiler stability determines final coil integrity and downstream usability.

2. Coil Capacity Classification

Recoiler must declare:

• Maximum coil weight
• Coil width capacity
• Coil inner diameter (ID) range
• Maximum outer diameter (OD)
• Maximum strip thickness

Typical industrial categories:

Category	Coil Weight Capacity
Light Duty	3–5 tons
Medium Duty	5–10 tons
Heavy Duty	10–20 tons
Structural / Civil	20–30+ tons

Safety margin requirement:

Minimum 25% above maximum operational coil weight.

3. Mandrel Specification (Critical)

3.1 Mandrel Expansion

Standard coil ID:

508 mm (20 inch)
610 mm optional

Mandrel must provide:

✔ Hydraulic expansion
✔ Uniform radial pressure
✔ Anti-slip surface
✔ Segment reinforcement

Expansion tolerance:

Radial uniformity ≤0.5 mm

Uneven expansion causes coil telescoping.

3.2 Mandrel Shaft Diameter

Minimum shaft diameter:

Coil Weight	Minimum Shaft Ø
≤5 tons	100 mm
5–10 tons	120 mm
10–20 tons	150 mm
20–30 tons	180 mm

Material:

4140 QT alloy steel
Heat treated
Fully ground

Undersized shafts flex under high tension.

4. Torque & Drive System

4.1 Drive Type

Acceptable systems:

✔ AC vector motor
✔ Servo-controlled torque system
✔ Gear-driven torque distribution

Torque must adjust dynamically as coil diameter increases.

4.2 Motor Sizing Benchmark

Coil Weight	Minimum Motor Power
≤5 tons	7.5 kW
5–10 tons	15 kW
10–20 tons	30 kW
20–30 tons	45–55 kW

Torque safety margin:

Minimum 30–40% above calculated load.

Undersized motors cause:

Loose wraps
Uneven tension
Edge wave

5. Tension Control System (Mandatory)

Recoiler must include:

✔ Closed-loop tension control
✔ Load cell feedback
✔ Dancer or loop pit integration
✔ Programmable torque ramping

Tension stability:

±5% deviation maximum.

Poor tension control causes:

Coil telescoping
Edge buckle
Strip camber

6. Alignment & Tracking

Recoiler must maintain:

Axial alignment tolerance ≤1 mm
Strip tracking stability
Side guide integration

Misalignment produces:

Offset coil layers
Side edge damage
Feeding instability

7. Over-Arm & Hold-Down System

Minimum requirements:

✔ Hydraulic hold-down arm
✔ Adjustable pressure control
✔ Anti-bounce stabilization

Prevents outer wrap lift at high speed.

8. Strip Separator System (Slitting Lines)

For multi-strip recoiling:

✔ Separator discs
✔ Strip comb system
✔ Independent strip alignment

Prevents strip overlap and edge damage.

9. Production Speed Compatibility

Recoiler must match line speed.

Typical ranges:

Application	Speed Range
Roll forming	15–40 m/min
Slitting line	80–150 m/min
Cut-to-length return	40–120 m/min

Torque system must compensate for diameter growth in real time.

10. Frame & Structural Rigidity

Minimum requirements:

✔ Fully welded heavy-duty frame
✔ Stress relieved structure
✔ Machined mounting surfaces
✔ Deflection under load ≤1 mm

High coil mass generates rotational inertia forces.

11. Safety Requirements

Minimum safety package:

✔ Guarding around rotating components
✔ Emergency stop circuits
✔ Anti-reverse mechanism
✔ Coil break detection
✔ Strip break detection

Recoiling high-mass steel coils presents severe hazard risk.

12. Coil Quality Standards

Recoiled coil must maintain:

Tight, even wraps
No telescoping
No edge damage
No excessive burr exposure
Uniform tension across width

Finished coil must feed smoothly into downstream equipment.

13. Factory Acceptance Test (FAT) Requirements

Supplier must provide:

• Full-load recoiling test
• Tension stability validation
• Alignment verification
• Diameter growth torque compensation test
• Speed validation at rated capacity

Edited or segmented footage is unacceptable.

14. Underspecification Red Flags

No torque feedback control
No declared tension tolerance
Undersized mandrel shaft
No coil weight safety margin
Mechanical brake-only system for heavy loads
No documented FAT protocol

These significantly increase coil integrity risk.

15. Cost Exposure if Underspecified

Potential consequences:

Coil rejection
Telescoped coil scrap
Downstream feeding failure
Production downtime
Customer complaints

Financial exposure can exceed $100,000–$1,000,000 annually in coil processing losses.

16. Machine Matcher Compliance Checklist

A recoiler is compliant when:

✓ Coil capacity includes ≥25% safety margin
✓ Mandrel expansion uniformity ≤0.5 mm
✓ Tension control within ±5% stability
✓ Shaft diameter meets weight benchmark
✓ Alignment tolerance ≤1 mm
✓ Full-load FAT validation complete

Machines failing these thresholds introduce exit instability across the entire coil processing line.