... medicine, accurate machine, accurate measure and inspection an Rods jewels are made of sapphire/ruby ,they are widely applied ... .Main types:sapphire/ruby rods jewels,single round end rods jewels,double round end rods jewels, jewel rotor laterl pin,etc ... 0.25Surface roughness: the surface for application: Rz0.05~ Rz0.2 MaterialSynthetic sapphire/ruby single crystal α-Al2O3, natural agate, spinel, ...