... structure.Processing: Chroming, Ceramic, Hard Chrome plating (Dupont formula), chrommantel compact, adhesion strong.Mirror, 3M grinding, Ra0. ... 005, finish14, Precision: temperature difference≤±1°C, thermal deformation≤0.01mm, concentricity≤0.001mm, straightness ... HRC55~58.2. Inner structure.3. Precision: temperature difference <= 1°C, heating transform <= 0.02mm, concentric <= 0.005mm ...