Mild Steel Roll Forming Material Guide: Coil Sizes, Thickness, Properties & Applications

Mild Steel Roll Forming Material

1. Overview of Mild Steel in Roll Forming

Mild steel is one of the most widely used materials in the roll forming industry due to its excellent balance of strength, formability, availability, and cost-effectiveness. It is a low carbon steel, typically containing between 0.05% and 0.25% carbon, which makes it softer and easier to form compared to higher carbon steels.

In roll forming, mild steel is commonly supplied in coil form and fed through a series of rollers to gradually shape it into specific profiles such as roofing sheets, purlins, channels, structural sections, and custom components. Its ductility allows it to undergo continuous bending without cracking, making it ideal for high-speed production lines.

Mild steel is typically used as a base material and may be further processed or coated depending on the application. Compared to galvanized or coated steels, it offers a lower initial cost but requires additional protection if used in corrosive environments.

2. Material Composition & Structure

Mild steel is primarily composed of:

• Iron (Fe): ~98–99%
• Carbon (C): 0.05–0.25%
• Manganese (Mn): 0.3–1.5%
• Trace elements: Silicon, phosphorus, sulfur

Structure:

• Homogeneous metal throughout (no coating unless specified)
• Smooth or lightly oiled surface finish
• Can be supplied as bare, oiled, or pickled

Unlike coated steels, mild steel does not have protective layers such as zinc or paint unless processed after forming.

3. Available Coil Specifications

Thickness Range

• 0.4mm – 6.0mm (common roll forming range: 0.5mm – 3.0mm)

Coil Width

• 600mm – 1500mm
• Custom slit widths available

Coil Weight

• 3 tons – 25 tons

Coil ID / OD

• ID: 508mm / 610mm
• OD: up to 1800mm

Flatness & Tolerance

• Thickness tolerance: ±0.02mm – ±0.05mm
• Camber control required for precision forming

4. Mechanical Properties

Typical ranges for mild steel used in roll forming:

• Yield Strength: 180 – 350 MPa
• Tensile Strength: 300 – 550 MPa
• Elongation: 20% – 35%
• Hardness: 120 – 180 HB

These properties make mild steel highly formable and suitable for complex profiles.

5. Coating Types (If Applicable)

Mild steel is usually supplied uncoated, but can be processed into:

• Painted steel (after forming)
• Powder coated components
• Galvanized after forming

Unlike PPGI or GI, coatings are not part of the initial material.

6. Surface Finishes

• Oiled finish (most common)
• Dry finish
• Pickled surface (scale removed)
• Light mill scale (hot rolled)

7. Common Roll Forming Applications

Mild steel is widely used across industries:

• Structural channels and beams
• C and Z purlins (before galvanizing)
• Steel framing profiles
• Automotive components
• Industrial racks and shelving
• Door frames and supports
• Cable trays
• Fence posts and structural members

8. Advantages of Mild Steel

• Low cost compared to coated materials
• Excellent formability
• Readily available worldwide
• Suitable for thick gauge forming
• Strong and durable
• Easy to weld and fabricate

9. Disadvantages / Limitations

• Poor corrosion resistance (requires coating)
• Can rust quickly if exposed
• Surface scale may affect forming
• Not suitable for exposed roofing without coating
• Requires post-processing in many applications

10. Roll Forming Machine Considerations

Roll Tooling

• Standard tool steel rollers suitable
• Chrome plating optional for longer life

Speed

• 10–60 m/min depending on thickness

Lubrication

• Often required to reduce wear

Cutting

• Hydraulic shear or flying cut-off
• Suitable for heavy gauge cutting

Common Issues

• Springback in thicker material
• Edge cracking if overworked
• Surface scratching if not lubricated

11. Common Problems in Production

• Rust formation during storage
• Oil contamination affecting downstream processes
• Coil camber causing profile deviation
• Inconsistent thickness affecting final profile
• Surface scale damaging rollers

12. Pricing Guide

Typical global pricing:

• Low: $500–$700 per ton
• Medium: $700–$900 per ton
• High: $900–$1200+ per ton

Factors affecting price:

• Thickness
• Grade
• Coil size
• Origin (China, EU, USA, India)
• Market steel prices

13. Comparison with Other Materials

Mild Steel vs Galvanized Steel

• Mild steel cheaper
• Galvanized offers corrosion resistance

Mild Steel vs Aluminum

• Steel stronger
• Aluminum lighter and corrosion resistant

Mild Steel vs Stainless Steel

• Mild steel much cheaper
• Stainless offers superior durability

14. Best Industries Using Mild Steel

• Construction and infrastructure
• Steel fabrication workshops
• Automotive manufacturing
• Industrial storage systems
• Agriculture equipment
• Energy and utility sectors

15. How to Choose Mild Steel for Roll Forming

Choose Mild Steel When:

• Cost is a key factor
• Product will be coated later
• Structural strength is required
• Indoor or protected use

Avoid Mild Steel When:

• Exposure to weather is high
• Corrosion resistance is critical
• Aesthetic finish is required

16. FAQ Section

What is mild steel used for in roll forming?

It is used for structural profiles, framing, channels, and components that may be coated later.

What thickness is best for mild steel roll forming?

Typically 0.5mm to 3.0mm depending on application.

Does mild steel rust during roll forming?

Not during forming, but it can rust quickly if not protected.

Is mild steel better than galvanized steel?

It is cheaper but lacks corrosion resistance.

Can mild steel be painted after forming?

Yes, it is commonly painted or powder coated after forming.

17. Machine Matcher Section

We supply roll forming machines for all material types including mild steel.

• Custom-built machines to your profile
• New machines built to specification
• Global delivery available
• UK and USA technical support

Contact:
Machine Matcher
Sales & Technical Team

Quick Specs

Thickness
0.5–3.0mm

Yield Strength
180–350 MPa

Coil Width
600–1500mm

Coil ID
508 / 610mm