Thanks for clearing that up. but the obvious difference may hinge on the manufacturing technology. While western rivets are done by precision tools and machines , China's are done roughly by human hands and eyes. That may not be true, but I am using that as an example.
Workmanship does reflect the stage of your industrial advancement level.
Maybe this has direct correlation to the WS-10A engine problem, the overall manufacturing process and technology is not good enough. Maybe time to introduce some new tools, process and manufacturing technology.