Material of metal face seal is chrome molybdenum cast iron Life: over 4500 hours ... 4500 hours.4,The hardness is HRC65-72,the working face precision within 0.015um, flatness up to 0.1um-0 ... excavators; (4)Various loaders and land levelers, cranes, mixers, mining machines, etc.(5) We accept OEM&ODM8,Introduction of our companyName ... ,Contact person: Name :Linda wang Mobile +86-15933963585 metal face seal