Beryllium Copper mold materials have hardness properties comparable to tool steels, but with superior thermal conductivity.
There is a four page document about how beryllium copper can be used for aerospace applications
Wear is moved from expensive (Titanium) parts and assemblies to easily replaceable,
lower cost beryllium copper parts with optimal wear and galling properties as well as excellent load capacity and corrosion resistance. Maintenance is required less frequently, and is less expensive to perform as a result.
Beryllium is more common than tin or uranium in the earth's crust but the production levels are tiny at about 600 tons per year.
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