My Gruen movement has Conoruma engraved on it. What does this mean?
Conoruma is Gruen’s proprietary alloy used for balance wheels and hairsprings. The Hamilton Watch Company used a famous, similar material called ‘Elinvar.’ These alloys are designed to be stable in spite of temperature changes they will expand or contract very little when the watch gets warm or cool. Because a watch is so delicate, changes in temperature will otherwise cause the watch to run slightly fast or slow. Balance and hairspring alloys like Conoruma help combat this problem.
