Standard Diameter: 3" / 3.00 InchesMetric Diameter: 76.2mmGrade: 100Material: AISI 52100 Chromium SteelBall Weight (each): 4.0 Pounds / 1.814 KilogramsChrome steel balls offer the precise geometry and fine surface finish that makes them especially useful for bicycles, casters, drawer slides, door locks and many other applications.