Strange Mainspring - How to Replace It

[Reuven Gruber]

I have a Korean Time-Strike movement made by Samsung
The mainspring is of a style I haven't seen - the spring has a ridge running down the center (see attached photo)

Two Questions
1. Can someone tell me something about this style
2. What should I replace it with
Look for a spring with a ridge [Where can I find one? - Not in Timesaver's catalog]
Use a regular spring (do I need to change the thickness, width or length to compensate for the lack of a ridge

[willofiam]

I would assume the ridge is for keeping the spring inline with itself, nice idea especially with those really long springs. Not sure if you can buy one with the ridge, timesavers has a replacement for the Korean 31 day clock movements...no ridge...here is the link, https://timesavers.com/search.html?q=ko ... &go=Search

I have never had to replace one of those mainsprings, they usually almost straighten out when taken out of the movement. Difficult to handle when trying to wind it back up, guess I dont know the secret to those yet.... Have fun!!!

[Bernie Weishapl]

I have worked on many of those movements. I have never replaced a spring except for 3 which were broken. I bought the replacement from Timesavers. Unless they are broken I have never seen one that needed to be replaced.

[Reuven Gruber]

Bernie

Half of one of the two mainsprings is missing

Do you by any chance have the Timesavers part number for the spring that you purchased

Best regards
Reuven