Hamilton 18s Motor Barrel #232 Mainsprings

[HUDD]

Can anyone please tell me if alloy equivalent mainsprings (#204 I think ? )are still available for the 940 motor barrel model, or if another equivalent will fit or can be modified to fit ? I have a bee in my bonnet about replacing steel mainsprings with unbreakable alloy ones having seen the damage that can result when one of the former breaks in service. Also, using my watches as carry watches in rotation I feel its better to be safe than sorry.
Hudd

[HUDD]

Can anyone please tell me if alloy equivalent mainsprings (#204 I think ? )are still available for the 940 motor barrel model, or if another equivalent will fit or can be modified to fit ? I have a bee in my bonnet about replacing steel mainsprings with unbreakable alloy ones having seen the damage that can result when one of the former breaks in service. Also, using my watches as carry watches in rotation I feel its better to be safe than sorry.
Hudd

[RL]

Hudd,
Try messaging Jack Kurdzionak and I think he can give you an answer as he deals in these alloy springs.

[Don Dahlberg]

To my knowledge these have been discontinued. The Hamilton number was 232. It was 3.18 mm wide, 0.18 mm thick and 25.25 inches long. The tough part of finding a substitute is the 3.18 mm width. I don't know of another mainspring with that width or close to it. Maybe a JA204 might work. It is 3.00 mm wide, 0.16 mm thick and 23.5 inches long. It is a bit short. The weaker strength does not bother me, because alloys are stronger than blue steel of the same thickness. They are both double brace, but slightly different in shape.

If anyone else has found a substitute, I would also like to know.

Don

[HUDD]

Thank you Randy & Don.
I shall follow up both your suggestions and keep you posted.
Hudd