... . If you have extra question, let us know.Materials: 20#, 45#, forge alloy steel (42GrMo,38GrMoAI), heating treatment and mechanical processing, ... Mirror, 3M grinding, Ra0.005, finish14, Precision: temperature difference≤±1°C, thermal deformation≤0.01mm, concentricity≤0.001mm, straightness≤ ... Mirror roller, Ra is up to 0.01, accurancy is 0.001 mm.Heating roller or cooling roller, inner structure, ...