Does anybody know where I could find main springs for my Seth Thomas World 15 day movement.

My first thought - Why do you want to change them?

But, if necessary the dimensions are 10'x3/4x.015.
You might try Timesavers, and you might have to buy a longer spring and shorten it.

Hi Larry: I agree with Dave in that Timesavers would be a good choice. I was going to replace the springs in my 30 day ST a few years ago. At that time TS had the correct springs and where very helpful, However when I had it tore down I found it had the original ST springs still intact. Even though it does not run for the full 30 days I chose to keep the original springs (Just wind it every 2 weeks ), John

Thank you for the advice I will try Time Savers

Larry

I have a 15 day with original springs and it will run about 18 - 20 days.