... accurate chronographs, auto-memorizing apparatus, precise instruments (micrometer, dial indicator) and other apparatus.Main types: Plane straight/olive holed bearing ... holed bearing, raised olive holed bearing, and single-cup raised olive holed bearing, etc.Main ... surface for application: Rz0.05~ Rz0.2 Assemble and sink surfaces: Rz3.2MaterialSynthetic sapphire/ruby single crystal α- ...