... beijing 2.resistance to strong acid strong alkali salt,high hardness,long life 1.Usage: bearing balls ... temperature, electric insulation, valve balls for acid, alkali, salt, measure pump, flowmeter and valve ball plunger for deep ... .2.Characteristic: resistance to strong acid, strong alkali, salt and gas of deleterious. long life, high hardness, ... to 1400°C,high electric insulation 300KV 99.5% AL2O3 balls