Casting Defect Guide
A quick reference for the most common high-pressure die casting (HPDC) defects. For an interactive diagnosis, use the Die Casting Defect Analyzer.
Defect reference
| Defect | Typical symptom | Common root cause |
|---|---|---|
| Cold shut / lap | Surface line where two flows didn't fuse | Low metal/die temperature; slow fill |
| Gas porosity | Holes/voids, leaks under pressure | Entrapped air; poor venting; excess lube |
| Misrun / short shot | Incomplete fill, missing features | Low temperature/pressure; thin walls |
| Hot tear | Cracks at corners/ribs | Constrained shrinkage; sharp corners |
| Blister | Raised bubbles after heating | Subsurface gas porosity |
| Flash / fin | Excess at parting line | Low clamp force; worn die |
| Warpage | Distortion after ejection | Uneven cooling; residual stress |
| Sink mark | Depression on thick areas | Shrinkage; poor feeding |
Prevention principles
- Control thermal balance. Stable, adequate metal and die temperatures prevent cold shut and misrun.
- Vent and fill cleanly. Good venting, overflows and gate design keep gas out of the part.
- Respect clamp force. Match tonnage to projected area to suppress flash.
- Design for shrinkage. Generous radii, uniform walls and balanced cooling reduce tearing and warpage.
- Maintain tooling. Regular die refurbishment preserves dimensional accuracy at volume.
Tip: symptoms often overlap. When in doubt, select everything you observe in
the Defect Analyzer to get a ranked shortlist of likely causes.