... 9SiCr,86CrMoV7,MC3A and so on Specification and sizes:210-650mm, 300-700, 400-750, 400-850, 180-500mm Classification Roll Body ... Diameter(mm) Grade Roller Body HardnessDepth of Hardening Zone (mm) Noxious Element Noxious Element Cold-rolling roller and ... porosity ≤3 Genter porosity≤3 Segregation≤3 Hot-rolling roller and roller blank 400-850mm 45Cr,55Cr,42CrMo,50CrMo, 60CrMo, ...