Pits Cluster
A group of small cavities in the surface, appearing together rather than as a single isolated void.
What causes it
- Gas porosity breaking through a machined casting surface
- Corrosion pitting, particularly at contact or crevice points
- Plating and coating faults
- Inclusions pulled out during machining
Why human inspection misses it
Individual pits are tiny. What matters is usually the cluster - its density and extent - and judging that by eye is subjective enough that two inspectors routinely disagree.
How it looks to a camera
Pits are small dark regions with consistent shape statistics, so density and distribution across an area can be measured rather than estimated. This is a class where a camera is more consistent than a person, not just faster.
Why it matters
Pit clusters concentrate stress and start fatigue cracks. On a sealing face they leak. On a casting they often indicate a process problem upstream rather than a one-off bad part.
Adam detects pits cluster along with five other defect classes. Upload a photograph of your part and see what it finds.