Carbon Fiber

Carbon fibers have several advantages including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion.

It is combined with other materials to form a composite like graphite, to form reinforced carbon-carbon composites, which have a very high heat tolerance. 

It is usually used to make pilot watches, dive watches and so on. Considering the cost, it is mostly use to make high quality watches and automatic watches.