Purlin Roll Forming Materials: C & Z Steel Coil Guide, Grades & Specs

Purlin Roll Forming Materials

1. Overview of Purlin Materials in Roll Forming

Purlin roll forming materials are structural steels used to produce C purlins, Z purlins, U channels, and structural framing components for buildings.

These materials are designed for strength, load-bearing capacity, and durability, making them critical in steel construction systems.

Compared to roofing and cladding materials, purlin materials are thicker, stronger, and less focused on appearance.

2. Main Types of Purlin Materials

1. Galvanized Steel (GI)

Most commonly used
Zinc coating for corrosion protection
Widely available

2. High Strength Galvanized Steel (S350GD / S450GD)

High yield strength
Reduced thickness with higher load capacity
Used in modern structural systems

3. Hot Rolled Steel

Used for heavy-duty applications
Lower cost for thick sections

4. Cold Rolled Steel

Better dimensional accuracy
Used for lighter structural profiles

5. Black Steel (Oil Coated / Dry)

Cost-effective
Requires further coating

3. Material Composition & Structure

Typical purlin material structure:

Steel base (structural grade)
Optional zinc coating (Z100–Z600)
Optional passivation or oil coating

4. Available Coil Specifications

Thickness Range

1.0mm – 4.0mm (standard purlin range)

Coil Width

100mm – 600mm (slit coil for purlins)

Coil Weight

3 tons – 10 tons

Coil ID / OD

ID: 508mm / 610mm
OD: up to 1500mm

5. Mechanical Properties

Typical values:

Yield Strength: 250 – 550 MPa
Tensile Strength: 350 – 650 MPa
Elongation: 10% – 25%

Common Grades

S250GD
S350GD
S450GD

6. Coating Types for Purlin Materials

Zinc Coating (GI)

Z100 – Z600
Provides corrosion protection

Passivated Surface

Reduces white rust

Oil Coating

Temporary protection during storage

7. Surface Finishes

Metallic galvanized finish
Oiled surface
Dry surface
Passivated finish

8. Common Purlin Profiles Produced

C purlins
Z purlins
U channels
Sigma profiles
Structural channels

9. Advantages of Purlin Materials

High strength-to-weight ratio
Excellent load-bearing capacity
Durable and long-lasting
Suitable for structural use
Widely available

10. Disadvantages / Limitations

Heavier than cladding materials
Requires precise roll forming setup
Higher material cost for high-strength grades
Limited aesthetic appeal
Requires corrosion protection

11. Roll Forming Machine Considerations

Roll Tooling

Heavy-duty rollers required
High strength materials need robust design

Speed

10–30 m/min

Lubrication

May be required for thicker materials

Cutting

Hydraulic cutting systems

Common Issues

Springback in high-strength steel
Tool wear
Profile distortion

12. Common Problems in Production

Springback affecting profile accuracy
Punching misalignment
Coil camber issues
Thickness variation
Edge cracking

13. Pricing Guide

Typical global pricing:

Standard GI Steel: $700–$1100/ton
High Strength Steel: $900–$1400/ton
Hot Rolled Steel: $600–$1000/ton

Factors affecting price:

Steel grade
Coating thickness
Coil thickness
Supplier

14. Comparison of Purlin Materials

S350GD vs S450GD

S350GD = standard structural
S450GD = higher strength, thinner sections

GI vs Black Steel

GI = corrosion resistant
Black steel = cheaper but needs coating

Hot Rolled vs Cold Rolled

Hot rolled = heavy-duty
Cold rolled = precision

15. Best Industries Using Purlin Materials

Steel building construction
Warehouses
Industrial buildings
Agricultural structures
Infrastructure projects

16. How to Choose Purlin Material

Choose Based On:

Load requirements
Span length
Environmental conditions
Budget
Coating requirements

General Guide:

Standard → S250 / S350
High load → S450
Corrosion resistance → GI coating

17. FAQ Section

What is the best material for purlins?

Galvanized high-strength steel (S350GD or S450GD).

What thickness is used for purlins?

Typically 1.0mm–4.0mm.

What coating is used?

Zinc coating (Z100–Z600).

Can purlin materials be roll formed?

Yes, they are designed for roll forming.

What is springback?

Material returning slightly after forming due to strength.

18. Machine Matcher Section

We supply roll forming machines for all purlin materials.

C & Z purlin roll forming machines
High-speed automatic systems
Custom-built solutions
Global delivery available
UK and USA technical support

Contact:
Machine Matcher
Sales & Technical Team

Quick Specs

Thickness
1.0–4.0mm

Yield Strength
250–550 MPa

Coil Width
100–600mm

Coil ID
508 / 610mm