Hamilton Factory 16s Mainspring Factory No. 317 - Steel

Hamilton Factory Mainspring for 16s Movements, Factory No. 317, steel, new in frail envelope.  These came available in a couple of different strengths and those that I can supply are shown in the drop-down list. See images for further details. The beautiful thing about factory mainsprings is that they always fit!  I likely have several of these so the one you get may differ slightly from the images. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.