Die casting forces molten aluminum or zinc into a steel die under high pressure. It produces complex, near-net-shape metal parts at high volume.
When it makes sense
- Volumes from a few thousand parts upward.
- Complex shapes with ribs, bosses and thin walls.
- Housings, heat sinks, brackets and hardware.
Quality points
- Porosity — trapped gas; critical for pressure-tight or plated parts. X-ray inspection can find it.
- Flash and parting lines — removed by trimming.
- Dimensional stability — machined features need secondary CNC work.
Cost structure
Die cost is significant, but unit prices fall sharply with volume. Always compare against machining at your expected quantity.
Aluminum vs. zinc die casting
- Aluminum (ADC12, A380) — light, strong, good heat dissipation; cold-chamber machines; typical for housings, heat sinks and automotive parts.
- Zinc (Zamak 3, Zamak 5) — excellent detail and surface for plating; hot-chamber machines with faster cycles; typical for hardware, handles and small decorative parts.
Secondary operations
Most die castings need trimming, deburring and CNC machining of critical faces and threads, then a finish: powder coating, painting, anodizing (limited on casting alloys) or plating for zinc. Include these steps in the quote so prices are comparable.
Die cost and life
Die-casting dies typically cost US$5,000–50,000+ depending on size and complexity. Aluminum dies wear faster than zinc dies because of higher temperatures — often around 80,000–150,000 shots for aluminum, several hundred thousand for zinc.
See die casting in China.
