Cold Rolled Steel Coils
Cold Rolled Steel Coils
At Emirerri Steel, we offer high-quality Cold Rolled Steel Coils (CR Coils) manufactured to meet international standards and diverse industrial requirements. Known for their exceptional surface finish, tight tolerances, and superior mechanical properties, our CR Coils are ideal for precision fabrication and critical applications across automotive, appliances, furniture, and construction sectors.
What Are Cold Rolled Steel Coils?
Cold Rolled Steel Coils are produced by rolling hot-rolled pickled steel through cold reduction mills at room temperature, followed by annealing and temper rolling. This process enhances the steel’s strength, surface quality, and dimensional accuracy.
Key Features
- Smooth and refined surface finish
- Uniform thickness and tight dimensional tolerances
- Improved mechanical strength and hardness
- Excellent formability and weldability
- Superior flatness for critical applications
Standards
ASTM A1008 / A1008M
ASTM A366
EN 10130
EN 10268
JIS G3141
Standard Dimensions
- Thickness:
- Range: 0.12 mm to 3.0 mm (commonly 0.3 mm to 3 mm).
- Thinner gauges (e.g., 0.12 mm to 0.5 mm) for precision applications like electronics or deep drawing.
- Thicker gauges (e.g., 1.5 mm to 3 mm) for structural or automotive uses.
- Width:
- Range: 600 mm to 2,100 mm.
- Common widths: 900 mm, 1,000 mm, 1,250 mm, 1,500 mm, 1,875 mm.
- Narrower widths (e.g., 600 mm to 1,000 mm) for specific cutting or slitting needs.
- Coil Weight:
- Range: 3 to 30 metric tonnes.
- Typical: 5 to 15 tonnes, depending on mill and customer requirements.
- Inner Diameter (ID):
- Standard: 610 mm (most common), sometimes 508 mm.
- Variations: 600 mm or custom sizes per agreement.
- Outer Diameter (OD):
- Range: 1,000 mm to 2,200 mm.
- Typical: 1,800 mm to 2,000 mm, limited by handling and transport constraints.
Tolerances
- Thickness Tolerance:
- Varies by standard, e.g., EN 10130, ASTM A1008.
- Example: For 0.5 mm to 1.0 mm thickness, tolerance might be ±0.05 mm; for 2.0 mm, ±0.08 mm.
- Width Tolerance:
- Typically ±0.5 mm to ±5 mm, depending on width and standard (e.g., EN 10131, JIS G3141).
- Flatness and Camber:
- Flatness: Often 5 mm/m or better for critical applications.
- Camber: Maximum 2 mm per meter of length (varies by spec).
Manufacturing Process
- Starting Material: Hot-rolled steel coils are pickled (cleaned with acid solutions) to remove surface scale and oxides.
- Cold Rolling: The pickled coils are passed through rollers at room temperature, reducing thickness (typically 0.12 mm to 3 mm) and shaping the steel into coils with tighter tolerances.
- Additional Steps:
- Electrolytic Cleaning: Removes lubricants and contaminants.
- Annealing: Heat treatment (batch or continuous) to relieve internal stresses, improve ductility, and enhance formability.
- Temper Rolling/Skin Passing: A light final roll to improve surface finish, flatness, and remove minor defects.
- Coating: Often oiled for rust protection or coated with zinc, galvalume, or other materials for corrosion resistance.
Applications
- Automotive body panels and structural parts
- Electrical enclosures and panels
- Kitchen appliances and white goods
- Office furniture and filing cabinets
- Home décor and lighting fixtures
- Precision tubes and profiles