The Steps of Aluminum Extrusion

Aluminum extrusion produces lightweight, durable, and corrosion-resistant products and parts for various industries. The extrusion process uses heat, pressure, stretching and cooling to mold aluminum into a predetermined shape.

What Is Aluminum Extrusion?

Aluminum extrusion is the process of shaping aluminum into hollow, semi-hollow or solid shapes known as extrusions. Extrusion heats aluminum to a molten consistency and pushes it through a die, where it takes on a new form.

Aluminum Extrusion Equipment

The following equipment plays a role in the aluminum extrusion process.

  • Ovens: Ovens preheat billets and extrusion dies so billets can easily flow through the dies.
  • Aluminum extrusion dies: An aluminum extrusion die is the steel disc that aluminum material passes through. This thick disc has an opening, and the material exits in the same shape as the die.
  • Hydraulic ram: The ram is the component that pushes the aluminum through the die. It applies force so the aluminum can move through the die and emerge smoothly through the opening.
  • Runout table: A runout table holds an aluminum pipe or tube after it exits the extrusion die. It also transfers the pipe or tube to a separate holding area.

Aluminum Extrusion Die Shapes

Dies are round tubes, channels and angles. They extrude the following shapes.

  • Hollow: A hollow die is a rectangular or square tube with one or multiple voids.
  • Semi-hollow: A semi-hollow die creates a curved C-shape with one partially enclosed void or narrow gap.
  • Solid: A solid die is an angle, rod or beam with no enclosed openings or voids.

Aluminum extrusion dies can also create complex shapes when industries have specific needs.

What Is Aluminum Extrusion Used For?

Aluminum is useful because it is lightweight and corrosion-resistant. It’s easy to work with and has high thermal stability, making it a long-lasting, durable material.

Because of its benefits, aluminum extrusion makes production easier. An aluminum extrusion’s properties enhance products by making them lighter and more durable. Companies can also request custom aluminum extrusions that meet their needs, expanding the types of products they can use them for.

What Industries Use Aluminum Extrusion?

The following industries use aluminum extrusion to produce and manufacture their products and equipment:

  • Architectural
  • Electronics
  • Automotive
  • Boating
  • Energy
  • Aerospace
  • Consumer goods manufacturers
  • Military and defense
  • Food packaging and processing
  • Construction

What Are the Aluminum Extrusion Steps?

Aluminum extrusion involves the following steps.

1. Extrusion Die Preparation

A technician pulls a round-shaped die from a warehouse or machines it from H13 steel and preheats it over 400 degrees Celsius. Preheating the die ensures the metal flows evenly while maximizing its life span. After preheating the die, the technician loads it into an extrusion press.

2. Aluminum Billet Preparation

A billet is a solid, cylindrical aluminum alloy block. After heating and loading the die into the extrusion press, a technician cuts a billet from a long aluminum alloy log. Next, the technician preheats the billet between 400 and 500 degrees Celsius, giving it sufficient malleability for extrusion without liquefying it.

3. Billet Transfer

After preheating the billet, a machine transfers it to an extrusion press. The machine applies a release agent or lubricant to the billet and extrusion ram to prevent them from adhering to each other, and then it loads the billet into the extrusion press.

4. Billet Movement Through the Extrusion Press

After the billet enters the extrusion press, a hydraulic ram applies pressure to push the billet into the extrusion press’s container. The ram can apply up to 15,000 pressure tons to move the billet into the container, and the billet material expands to fill the container’s walls.

5. Billet Emergence

The aluminum billet material presses against the die as it fills the extrusion container, and the continual pressure eventually pushes the billet material through the die’s opening. The material emerges in the shape of the extrusion die.

6. Cooling

A puller grips the aluminum extrusion as it comes out of the die and guides it across a runout table. Fans or a water table cool the extrusion as it moves along the table through a process known as quenching. While this cooling process reduces the extrusion’s temperature, it does not entirely cool until later in the process.

7. Extrusion Separation and Room-Temperature Cooling

As an aluminum extrusion extends across a runout table’s entire length, a hot saw shears it. Shearing the extrusion cuts and separates it from the extrusion equipment and process. After the saw shears the extrusion, the runout table transfers it to a cooling table. The extrusion remains on the cooling table until it reaches room temperature.

8. Stretching

Extrusions twist naturally during extrusion, so a technician moves them to a stretcher. The stretcher mechanically grips each end of the extrusion and pulls it in opposite directions until it’s straight and meets specifications.

9. Cutting and Aging

After the extrusion straightens and hardens, it moves to a saw table. At this stage, the extrusion’s properties have a T4 temper or hardness. The saw table cuts the extrusion to a pre-specified length, and a technician moves the extrusion to an aging that increases the extrusion’s temper from T4 to T5 or T6.

10. Heat Treatment and Finishing

Technicians enhance an extrusion’s properties via heat treatment after it reaches the proper hardness. Following heat treatment, technicians apply surface finishes to increase corrosion prevention and polisy the extrusion’s appearance. Technicians may also perform fabrication operations such as cutting, punching, deburring, machining or drilling to achieve the desired dimensions.

Pennex Aluminum Company’s Extrusion Capabilities

Pennex Aluminum Company can produce aluminum extrusions up to the following dimensions:

  • 60 feet maximum length
  • 16-inch maximum profile widths
  • 20 pounds-per-foot maximum weight

We have advanced equipment and over 40 years of experience, enabling us to produce standard, tight tolerance and custom aluminum extrusions. We can provide the following types of extrusions:

  • Angles
  • Channels
  • Square or rectangular bars and tubes
  • Tees
  • Zees
  • I-beams
  • Hex bars
  • Rods
  • Round tubes
  • Pipes

Trust Pennex Aluminum Company With Your Aluminum Extrusion Needs

Aluminum extrusion produces essential parts and products for various industries. Pennex Aluminum Company offers aluminum extrusion services to meet each customer’s expectations.

We create custom extrusions to fit your unique specifications, and we work quickly and efficiently to ensure you meet your deadlines. Contact us to learn more about aluminum extrusion services and how we can produce extrusions that match your specifications.