Die Castings
Die casting forms metal parts in reusable steel dies, giving accurate, repeatable castings with good surface finish in aluminium, zinc and copper alloys. It is very economical at medium to high volumes, with gravity and pressure die casting as the main variants.
What it is
Molten metal fills a precision steel die, either by gravity or under high pressure, and solidifies quickly. The die opens, the part is ejected, and the cycle repeats, producing many parts from one tool.
Die castings need less machining than sand castings and have thinner walls and finer detail, but die cost means volumes must justify the tooling.
Typical applications
- Motor and pump housings
- Automotive and two-wheeler components
- Electrical enclosures and heat sinks
- Appliance and tool bodies
- Brackets and covers
Suitable materials
- Aluminium alloys (ADC12, LM6, LM24, A380)
- Zinc alloys (Zamak)
- Brass and copper alloys (limited)
Points to consider
- Die cost is significant; economical from thousands of parts.
- Design with uniform walls, draft and radii for good filling.
- High-pressure die castings may have porosity; limit machining depth on sealing faces.
- Choose gravity die for heat-treatable, lower-porosity parts.
Frequently asked questions
What is the difference between gravity and pressure die casting?
Gravity die casting fills the die by gravity, giving sound, heat-treatable parts. Pressure die casting injects metal at high pressure, allowing thin walls and high output but with more porosity.
Which metals can be die cast?
Mainly aluminium and zinc alloys, with some copper alloys. Steel is not die cast.
When is die casting economical?
At medium to high volumes, typically thousands of parts, where the die cost is spread across many castings.