... balls scope form 0.8mm to 50.8mm and the precision levels are G3, G5, G10, G16, G20 etc. ... Low density, high strength, high hardness, high toughness, corrosion-resistant, abrasion-resistant, anti-oxidation, thermal vibration, low-expansibility, self-lubricating, Si3N4 ... bearing industry and chemical industry. The indexes of each precision level of ceramic balls are following: GradeVdwsSPHVdwlRaG30.05-0 ...