DIE CASTINGAluminum · Zinc · Dies · Machining · Finishing
Design for manufacturing
Design rules that make die castings better and cheaper
Many die casting defects start on the drawing: porosity, cold shuts, sink marks, warpage and parts sticking in the die. The fixes are well known. Keep walls thin and even, add draft, radius the corners, replace thick sections with ribs, and decide early where the metal enters and where the air leaves.
We check every new part against these points and send DFM comments before die design starts. The values below are typical starting points; flow length, part size and alloy change them.
What our DFM review checks
- Wall thickness and thick-to-thin transitions
- Draft on walls, ribs and cores
- Fillets and radii at corners
- Ribs and bosses, cored out where thick
- Undercuts that need slides
- Gate, overflow and vent locations
- Machining allowance and datums
- Porosity-critical and leak-tight zones
Die casting design guidelines (typical)
| Wall thickness | Aluminum: typically about 1.5–4 mm; zinc: thinner possible; keep walls uniform |
|---|---|
| Draft | Aluminum: typically about 1–2°, more on inner walls and cores; zinc: about 0.5–1° |
| Fillets | Radius all inside and outside corners; avoid sharp corners |
| Ribs | Thinner than the adjoining wall, with draft and root radii |
| Bosses | Cored out and tied to walls with ribs |
| Holes | Cored holes need draft; precise holes are machined |
| Machining stock | Typically a few tenths of a millimeter up to about 1 mm |
| Tolerances | General tolerances to ISO 8062-3 or NADCA; tight features are machined |
Design FAQ
Why are uniform walls important in die casting?
Metal in thick sections solidifies last and shrinks, which causes porosity and sink. Uniform walls fill and solidify evenly, so there are fewer defects and the cycle is shorter.
Can die castings have undercuts?
Yes, with slides or core pulls in the die, which add cost and maintenance. Redesigning a feature to avoid the undercut often lowers die cost.