Does anyone have the numbers and sizes for the 3 different mainsprings for a Hamilton 992b?
Thanks
Ed

Ed, # 534, 534B & 354 are the ones that I believe are for a 992B....I could be wrong, there will be others that may set us straight....

Good Luck,

Regards,

Jerry

I have a 1951 992b that I can only get a 24 hour run out of. I have an extra Dynavar #35434 standard strength 370. I do not know which spring is in it until I take it apart and measure it. It could be the weaker of the three, or it could be the standard 370. I wanted to get a heads up on the numbers of the three to make a decision when I get all the info together.
Ed

Ed,
These charts should be useful.
RR

From 1951 Hamilton Watch Materials Page

Here are some newer numbers.
RR

From 1961 Hamilton Parts Catalog Page 82

Richard, thank you very much. That is exactly what I was looking for.
Ed