Cater Accessories: 1.2M0344,5M8647,6T8440,7T0158,9G5313,9W6686,9W7211 2.diameter:50-1,000mm 3.GCr15 4.ISO9001:2000 Cater Accessories: Cater Accessories are used in construction machinery and mining machinery , the outer diameter is from 50mm-1,000mm. The material is chrome molybdenom casting iron. The hardness is HRC58-62 , the working face precision within 0.015um , flatness up to 0.1um-0.2um , ...