Spinner Doubler Cracks

[LordofWar]

My CS spinner backplate doubler ring is cracked. Noticed just as we were about to install. Interesting thing is, the prop had a ring and reseal done when it wasn't brought to my attention.

https://drive.google.com/file/d/1sV5...ew?usp=sharing

[Ralph Inkster]

Have ran into cracks in the ring similar to yours.
Have also ran into cracks in bulkhead but the ring was ok.
Have found the odd rivet head missing, ring & bulkhead ok.
Only once I found crack through both but that spinner definitely showed signs of being over torqued.
I know the cause of the last one, would be curious what caused the other 3.