What Rocker Arms Are These?

In the instances I’ve seen them be a problem, it’s been one rocker welding itself to the shaft.
The other 15 are still perfect......... as well as the shafts, in the other 15 positions.

It also took a period of time before they had an issue.
A couple of seasons of regular bracket racing.
The first one I chalked up to “**** happens”, after the second one(different engine), I decided I wouldn’t be running them with roller cams anymore.
The third one was being run with a SFT cam with beehive springs, and had seen a lot of racing and probably 10k street miles before it had an issue.
I blamed that one on the oil.