Specifications: Ball Diameter: 3mm Finished: Mirror Polished Material: Carbon Steel Package Contents:200 x Precision BallsDescriptions: Carbon steel provides material properties that are acceptable in many applications, especially those where rust or corrosion is not a concern. Carbon steel bearing balls are used as components for bearing loads. The specific applications are casters, drawer slides, locking mechanisms, semi-precision bearings, and lots of other industrial and consumer products. Notice: Please confirm the Ball Diameter you are ordering.