Originally Posted by
sooty655
But the defect wasn't detected in the billet, or at any subsequent manufacturing stage, so a theoretical ability to track it through the process doesn't help. Similar defects might be in similar places in other discs from the same billet, but defects in other discs could be anywhere unless/until the prime defect cause in the billet is known.
If the defect was suspected to be linked to a specific billet seems that only a relatively few discs would need to be inspected. Not clear from the items posted here if that is the case.
The inspections will probably be more general and will be looking for defects that either escaped original inspections (or more likely) grown over time so they now can be detected if present.
Either way would be surprised if inspections did not include the entire disc unless some design feature was identified that stressed one position more that others.
I don't have specific knowledge but would seem the discs would have be very symmetrical and balanced parts.