How Are Steel Extrusions Made? A Step-by-Step Guide
Steel extrusions, whether they come in the form of tubes, rods, angles, or channels, are the unsung heroes of countless construction and industrial projects. Their inherent strength, durability, and versatility make them essential for a range of applications, from large-scale infrastructure to precision components in manufacturing.
Despite being so widely used, many people don’t know the fascinating process behind how these extrusions are created—the extrusion process. Let’s dive deeper into each step and explore how these reliable components are made.
At MG Metals, we supply a wide range of stainless steel and mild steel extrusions, expertly tailored to meet the needs of your project. Below, we’ll guide you through the entire extrusion process, from billet preparation to finishing.
1. Billet Preparation and Heating
The first stage begins with the preparation of the billet—a solid, cylindrical or rectangular piece of steel. This billet is heated to temperatures between 1,100°C and 1,300°C (depending on the type of steel being extruded).
- Why Heating Matters: At these temperatures, the steel becomes malleable but retains enough structural integrity to undergo shaping.
- Heating Methods:
- Induction Heating: Energy-efficient and precise, often used for rapid heating.
- Flame Heating: Direct application of flames to raise the temperature.
- Furnace Heating: Effective for bulk billet preparation, especially in large-scale production.
2. Extrusion Pressing
Once heated, the billet is transferred to the extrusion press. This is where the real transformation happens.
- The Process: High pressure is applied to the billet, forcing it through a specially designed die.
- Types of Extrusion:
- Hot Extrusion: Performed at high temperatures to reduce force requirements.
- Cold Extrusion: Used for steel that requires tighter tolerances and improved surface finishes.
The resulting steel takes on the cross-sectional shape of the die. This step determines the final profile—be it rods, tubes, angles, or channels.
3. Die Designing: Shaping the Steel
The die is the star of the extrusion process. Made of hardened steel, the die defines the final shape of the extruded component.
- Why Dies Are Critical: The precision of the die impacts the accuracy, strength, and functionality of the extrusion.
- Custom Profiles: At MG Metals, we offer bespoke solutions—dies can be designed to create standard profiles like rods, channels, and tubes, or complex, custom shapes based on your specifications.
Pro Tip: Understanding the right steel extrusion profile can improve material usage and reduce waste.
4. Extrusion Cooling
Once the steel has been extruded, it needs to be cooled to harden and stabilise its structure. This step improves the mechanical properties of the material.
- Cooling Methods:
- Air Cooling: Slower and controlled, ideal for avoiding thermal stress.
- Water Cooling: Faster cooling for projects requiring quick processing.
The chosen method depends on the grade of steel and the intended application of the extrusion.
5. Cutting and Precision Finishing
After cooling, the extruded steel is cut to the required lengths. At this stage:
- Steel can be cut while hot or after cooling using techniques like sawing, shearing, or precision cutting.
- The lengths can be customised to meet the specific needs of your project, saving time and resources on-site.
6. Heat Treatment (Optional)
For steel that requires additional strength, durability, or specific mechanical properties, heat treatments are applied:
- Annealing: Softens the steel for easier machining.
- Normalising: Refines grain structure, improving strength and toughness.
- Quenching and Tempering: Hardens steel and improves resistance to wear and fatigue.
At MG Metals, we supply heat-treated steel extrusions suitable for even the most demanding projects.
7. Finishing
The final step is finishing, where the extruded steel undergoes treatments to enhance its performance, appearance, and corrosion resistance:
- Surface Treatments:
- Pickling: Removes impurities and scales from the surface.
- Passivation: Enhances corrosion resistance, especially for stainless steel.
- Galvanising: Adds a protective zinc coating for long-lasting durability.
- Coatings:
- Powder Coating: Provides a durable, aesthetic finish in various colours.
- Electroplating: Adds a protective or decorative metallic layer.
By ensuring proper finishing, steel extrusions can withstand harsh environments while maintaining a polished appearance.
Why Choose MG Metals for Steel Extrusions?
At MG Metals, we’re more than just suppliers—we’re your project partners. Here’s why our customers trust us:
- Custom Solutions: We precision-cut steel extrusions to your exact specifications.
- Fast Turnaround: We aim to process and ship your order within 2-5 days, keeping your projects on schedule.
- Quality Materials: From stainless steel to mild steel, we deliver components that meet the highest industry standards.
Shop Premium-Quality Steel Extrusions By MG Metals
MG Metals is the UK’s leading provider of custom-cut steel components. We specialise in delivering precision-cut pieces that perfectly meet your specific requirements, no matter how complex.
Get a quote on steel extrusions online or call us on 01794 521070 today. Our team of experts are always happy to help you find the perfect solution for your needs, so don’t hesitate to get in touch!