Question:

When one is looking for a replacement hairspring[say a NOS or salvage part is not going to happen!],what are and how does one determine the correct dimensions for the"new" h/s?

I would assume thickness,type of steel/material,and number of coils? Also assuming that an overcoil could be formed from a flat one if a breuget overcoil was not available.

Really curiuos,

Sam Williamson
NAWCC 154312
IHC Charter Member 14
Member Chapters 96 and 185