Standard Diameter: 17/64" / .2656 InchesMetric Diameter: 6.747mmGrade: 25Material: AISI 52100 Chromium SteelBall Weight (each): .0441 Ounces / 1.25 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.