Very cool. I became fascinated with bells after watching this [0] documentary on how they are made a few years ago (it's in German, but that hardly matters, just watching the process is extremely interesting).
The whole process is a combination of extreme sophistication and extremely simple tools and materials, something that has become quite rare nowadays. And despite an exact calculation of the bell shape and thousands of years of trial and error, tradition, and experience (the foundry in the video has been owned by the same family for 300 years), the cast is still highly dangerous and it still regularly happens that the bell just doesn't come out right and cannot be saved - months of work for nothing.
I think that explains why on the day of the cast (which is just 1 or 2 times per year), everyone involved is extremely nervous. The bell founder and the customer all join in prayer, and the cast traditionally starts with "in God's name" [1].