Pressure Die Castings
High-pressure die casting (HPDC) injects molten aluminium or zinc into a steel die at high speed and pressure, producing thin-walled, detailed, near-net parts in seconds. It is the most economical casting method for high volumes of complex non-ferrous parts.
What it is
Cold-chamber machines (aluminium) or hot-chamber machines (zinc) force metal into the die in milliseconds, then hold pressure as it solidifies. Parts come out with fine detail, thin walls and good surface finish, often ready for minimal machining.
Die costs are high, so HPDC suits large production runs such as automotive and appliance components.
Typical applications
- Automotive and two-wheeler housings
- Motor end covers and fan housings
- Electrical enclosures and heat sinks
- Power-tool and appliance bodies
- Lighting fixtures
Suitable materials
- Aluminium (ADC12, A380, LM24)
- Zinc alloys (Zamak 3, 5)
- Magnesium alloys
Points to consider
- Porosity is inherent; avoid deep machining on sealing faces or use vacuum-assisted casting.
- HPDC parts are generally not heat treated.
- Die cost is high; confirm volumes before committing.
- Design ribs and uniform walls for good filling.
Frequently asked questions
Why is pressure die casting used for high volumes?
Cycle times are seconds and parts need little machining, so part cost is very low once the expensive die is paid for.
Can pressure die castings be welded or heat treated?
Generally no, because trapped gas porosity blisters when heated.
How thin can walls be?
Down to about 1–2 mm in aluminium and even thinner in zinc, depending on part size.