Pack of 100 Loose 1/16" inch Tungsten Carbide Ball Bearings 1/16" inch = 0.063" inch G25 100 Loose Balls Pack of 100 Loose 1/16" inch Tungsten Carbide Ball Bearings, Balls are made of tungsten carbide, Balls size is 1/16" inch (1.6mm), Grade is G25, And it meets grade 25 sphere tolerancem, Loose Ball is extremely hard alloy made from tungsten and carbon And it is high corrosion wear resistance.