Spring barrel for a timepiece, a watch or a clock, where the spring is made of a metal alloy including nitrogen, iron, carbon, manganese, chromium, niobium and niobium

摘要

The spring barrel for a timepiece, is claimed. The spring is made of a metal alloy including nitrogen in a proportion of 0.75-1 wt.%, and iron. A ratio of an interior diameter of eye and a thickness of plate is less than 12. An independent claim is included for a timepiece.