Casting aluminium is a manufacturing process that covers several distinct die casting methods, each suited to different combinations of volume, wall section, alloy and post-casting requirement. This guide covers the three main methods, what makes aluminium the default choice across industrial manufacturing, and where each die casting process fits.

The three casting aluminium processes

There are various casting methods available to produce aluminium parts:

High-pressure die casting (HPDC)

Aluminium high-pressure die casting injects molten metal into a hardened steel die at pressures up to 1,000 bar. The shot completes in under a second, filling fine cavity detail before the aluminium alloy cools. The result is a dense, thin-walled finished component with good dimensional accuracy and a smooth surface finish.

HPDC is the process for high-volume, repeatable production. A well-maintained die runs to hundreds of thousands of identical parts. Lupton & Place operates Buhler Real-Time Closed Loop Control machines from 160 to 1,300 tonnes locking force, including the Buhler CARAT 130, the first of its type installed in a UK foundry.

Gravity die casting

Gravity die casting pours molten aluminium into a permanent steel mould under gravity alone. The slower fill produces lower gas porosity than HPDC, making gravity castings better suited to post-casting heat treatment or welding. Tooling costs are lower than HPDC, so the process works well at low-to-medium volumes. We operate a tilt-gravity plant, which reduces turbulence further and improves mechanical properties.

Structural die casting

Structural die casting uses vacuum technology to remove gas from the die cavity before injection, producing castings with the internal integrity needed for load-bearing and safety-critical applications. It is the process used for EV battery enclosures, chassis components and other structural automotive parts where welding or heat treatment is required after casting.

Which process is right for your component?

Volume: HPDC pays back its tooling cost above roughly 10,000 parts per year. Below that, gravity or sand casting is usually cheaper per part.
Complexity: HPDC handles the tightest geometries and thinnest walls. Gravity suits moderate complexity. Sand is the most flexible but least precise.
Heat treatment or welding: Gravity casting is the safer choice. Trapped gas in HPDC parts creates porosity in the weld zone. Structural vacuum die casting removes that constraint.
Alloy: The cast aluminium alloys used in HPDC prioritise fluidity under pressure. Gravity casting alloys trade some fluidity for better mechanical properties.

Specialist engineers review component designs before tooling is committed. Getting involved at that stage is where process and geometry changes cost the least.

Why aluminium is the default casting metal

Weight: Approximately one-third the density of steel. In automotive, that means lighter vehicles; in EV applications, more range.
Corrosion resistant: Aluminium forms a natural oxide layer and does not need surface coating to hold up in most industrial environments.
Thermal conductivity: Conducts heat roughly four times better than steel, making it standard for heat sinks, LED driver housings and electrical enclosures.
Recyclability: Recycled aluminium requires approximately 5% of the energy used to produce primary aluminium from ore.

Where casting aluminium is used

Automotive industry and EV: Engine blocks, gearbox housings, brake callipers and structural body components are standard casting aluminium parts for automotive applications. EV powertrain housings, battery enclosures and inverter cases are now high-volume requirements. We’ve produced components for BMW, Jaguar Land Rover, Nissan, Toyota, Scania and Iveco, including brake system parts for most of the world’s leading commercial vehicle brands.

Electronics: Enclosures, heat sinks and motor end caps. LED driver housings are a useful example: the same casting manages heat dissipation and holds the tolerances that optical fitment requires.

White goods: Pump housings, motor frames and compressor components. Detergent environments are aggressive; aluminium holds up without additional surface treatment.

Lighting and construction: Die-cast housings are standard in commercial lighting for heat management and finish consistency. In construction, architectural hardware and structural access equipment use aluminium for its strength-to-weight ratio and end-of-life recyclability.

Have a casting requirement?

Lupton & Place is an ISO 9001:2015 certified aluminium die casting foundry in Burnley, Lancashire, producing over 5 million castings a year for customers across Europe.

We can produce LED housings, automotive components and other parts for consumer products that offer excellent corrosion resistance. Whatever you need, we can assist you.

If you have a component specification or a question about process selection, call our engineers on 01282 422361 or use the contact form.