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