A hook for a fusee chain
An unusually small lever fusee watch came to me
missing its fusee hook. This shows the new hook filed
from a piece of blued steel. There is a beard hair for
scale in the photo (a dime is way too big.)
More photos inside!
When making a part like this, do the thing that's most likely to fail first if possible: drilling the hole. This is about 0.2 mm diameter. Then, file the part around it. Detach it from the "handle" only when absolutely necessary, it gets really hard to handle once detached.
Then, rivet it into the chain.
Finally, detach the handle and make sure it pivots correctly, check the whole
chain carefully, and finally test. I like to test chain repairs with the gear
train not installed, just in case there's a second break.
Riveting!