... corundumGeneral DescriptionOur company have specialised in the manufacture of Jewel bearings Synthetic white corundum, ruby, sapphire, glass, ... microcrystalline glass, cubic zirconia, natural agate bearing, etc.Jewel bearings have application in apparatus, meter and ball bearing, ... -hole thin magnetic ring are widely used in watch,clock,micro-motor,meters,optical communication and other ...