Porosity is one of the most common concerns in aluminum casting. The real question for buyers is not whether tiny pores can exist, but whether they affect machining, sealing, strength, appearance, or assembly use.
This article is written for buyers preparing a casting RFQ. The best answer still depends on the drawing, material, quantity, machining areas, and inspection requirements.
Where Porosity Becomes a Problem
- Sealing faces on pump, valve, fluid, and compressor components.
- Machined bores, threaded holes, bearing seats, and thin wall areas.
- Visible surfaces after coating, polishing, or surface treatment.
- Pressure-related parts where leakage or testing may be required.
What Should Be Reviewed Early
- Wall thickness, ribs, bosses, hot spots, and areas where metal flow may be difficult.
- Casting process choice: die casting, gravity casting, low pressure casting, or sand casting.
- Machining allowance around sealing faces, holes, and functional surfaces.
- Inspection method: visual inspection, section check, X-ray, pressure/leakage test, or agreed acceptance standard.
How Buyers Can Reduce Risk
- Mark sealing areas and machined surfaces clearly on the drawing.
- Tell the supplier if the part will hold pressure, fluid, or vacuum.
- Confirm whether porosity acceptance is cosmetic, dimensional, or functional.
- Discuss inspection requirements before production, not after shipment.
Related Pages
Aluminum Die Casting ServicesGravity Casting ServicesQuality ControlAluminum Motor Housing Casting Case
FAQ
Can aluminum casting porosity be completely avoided?
The target is usually control, not a vague promise of zero pores. The acceptable level depends on the part function, machining areas, and inspection standard.
When should X-ray or leakage testing be discussed?
Before quotation, especially when the part has sealing faces, pressure areas, or internal cavities that cannot be judged by appearance alone.
