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Brass
From WikiPedalia
An alloy of copper and zinc, in the proportion of about two parts of copper to one part zinc. The zinc makes brass stronger and harder than copper is alone. It is easy to work, and doesn't rust. Most spoke nipples are made of brass, because it is easy to thread and will not corrode onto the spoke threads.
Brass is also easy to cast, and has been used for derailer parts and quick-release skewer acorn nuts, and for thrust washers in caliper brakes. Various special brass alloys are used as filler material for brazing.
