What Steel Materials Are Used in Roll Forming? Complete Material Guide
Roll forming uses a range of steel materials selected based on strength, corrosion resistance, and application. The most common materials are coated steels for roofing and cladding, and higher-strength steels for structural products.
The main steel materials used in roll forming include:
1. Galvanized Steel (GI – Most Common)
Galvanized steel is the most widely used material in roll forming.
Key features:
- Coated with zinc for corrosion protection
- Good formability
- Cost-effective
Typical uses:
- Roofing panels
- Wall cladding
- Purlins
- General construction profiles
Coating types:
- Z100, Z120, Z180, Z275 (grams of zinc per m²)
This is the standard material for most roll forming applications worldwide.
2. Pre-Painted Steel (PPGI / PPGL)
Pre-painted steel is galvanized or Galvalume steel with a paint coating.
Key features:
- Available in various colors and finishes
- Corrosion-resistant
- Aesthetic appearance
Typical uses:
- Roofing panels
- Wall cladding
- Architectural panels
This is commonly used where appearance is important, such as residential or commercial buildings.
3. Galvalume Steel (Al-Zn Coated Steel)
Galvalume steel is coated with aluminum and zinc.
Key features:
- Better corrosion resistance than standard galvanized steel
- Longer lifespan in harsh environments
- Good heat reflectivity
Typical uses:
- Roofing systems
- Industrial buildings
- Coastal or high-humidity environments
This material is widely used in premium roofing applications.
4. Cold Rolled Steel (CR Steel)
Cold rolled steel is uncoated steel with a smooth surface.
Key features:
- High precision
- Good surface finish
- Higher strength than hot rolled steel
Typical uses:
- Light gauge steel framing
- Automotive components
- Appliance parts
It is often used where coating is not required or is applied later.
5. Hot Rolled Steel (HR Steel)
Hot rolled steel is used for thicker and heavier profiles.
Key features:
- Lower cost than cold rolled
- Suitable for heavy-duty applications
- Less precise surface finish
Typical uses:
- Structural profiles
- Heavy-duty components
- Industrial applications
6. High Strength Steel (HSS / High Tensile Steel)
High strength steel is used for structural and load-bearing applications.
Key features:
- Higher yield strength (e.g., 350 MPa, 550 MPa)
- Stronger and lighter structures
- More difficult to form
Typical uses:
- Purlins and structural profiles
- Automotive parts
- Heavy-duty roll formed products
This material requires stronger machines and tooling.
7. Stainless Steel
Stainless steel is used in specialized applications.
Key features:
- Excellent corrosion resistance
- High durability
- Higher cost
Typical uses:
- Food processing equipment
- Medical and clean environments
- Architectural applications
8. Aluminum
Although not steel, aluminum is commonly used in roll forming.
Key features:
- Lightweight
- Corrosion-resistant
- Easy to form
Typical uses:
- Roofing and cladding
- Architectural panels
- Transport applications
Material Grades and Strength
Steel used in roll forming is also defined by its yield strength, which affects how it forms.
Typical grades include:
- G250 (standard strength)
- G350 (structural strength)
- G550 (high tensile roofing steel)
Higher strength materials:
- Require more forming force
- Need precise tooling
- Can increase machine wear
Coating and Surface Options
Steel used in roll forming often includes coatings for protection:
- Zinc (galvanized)
- Aluminum-zinc (Galvalume)
- Paint coatings (PPGI/PPGL)
- Anti-fingerprint coatings
These coatings improve durability and performance.
Choosing the Right Material
Material selection depends on:
- Product type (roofing, structural, etc.)
- Environment (coastal, industrial, dry)
- Required strength
- Budget
For example:
- Roofing → PPGI or Galvalume
- Purlins → galvanized high-strength steel
- Structural → high tensile or hot rolled steel
Machine Considerations
Not all machines can handle all materials.
Factors include:
- Thickness range
- Material strength
- Coating type
Using the wrong material can cause:
- Poor forming quality
- Tooling damage
- Increased wear
Frequently asked questions:
What is the most common material in roll forming?
Galvanized steel (GI) is the most widely used.
What is the best material for roofing?
PPGI and Galvalume are the most common choices.
What material is used for purlins?
High-strength galvanized steel (e.g., G350 or higher).
Can stainless steel be roll formed?
Yes, but it requires specialized machines and tooling.
What is the difference between GI and Galvalume?
GI uses zinc coating, while Galvalume uses aluminum-zinc for better corrosion resistance.
In summary, roll forming uses a wide range of steel materials, with galvanized and pre-painted steels being the most common for construction, and higher-strength steels used for structural applications.
Choosing the right material is critical for product quality, durability, and overall production efficiency.