I initially thought that the flatness of the clapper was due to wear over the past 80 years or so. However I’m having second thoughts. The flat spots on each side of the clapper on the 48″ cast iron bell are so large, while there is no noticeable wear on the inside of the bell itself. It now seems to me that it is also possible that the flat sections of the clappers could have been done intentionally at the factory. The clappers could have been grinded or filed down at the factory in order to get the right tolerance (between the clapper and the bell) for the spring to do its job properly. Or might the factory have filed the flat spots on the clapper to reduce the chances of cracking the bell? Any other thoughts on this?
Thanks, Henry