Standard Diameter: 9/16" / .5625 InchesMetric Diameter: 14.2875mmGrade: 25Material: AISI 52100 Chromium SteelBall Weight (each): .42032 Ounces / 11.916 GramsChrome 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.