Standard Diameter: 11/16" / .6875 InchesMetric Diameter: 17.4625mmGrade: 25Material: AISI 52100 Chromium SteelBall Weight (each): .76742 Ounces / 21.756 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.