Tungsten carbide balls are used where extreme hardness and wear resistance is required; in such applications as bearings, ball screws, valves and flow meters. These balls are also used for coining and as pivots, detents and tips for gauges and tracers. Tungsten carbide itself is practically inert and extremely strong. Any attack is usually on the binder. Since other material is less expensive, the selection of tungsten carbide solely for corrosion resistance is usually not justified. The surface roughness and accuracy grades of polished balls should respectively confor to the requirement of Grade 3,5,10,25,50,100,200,500,1000. Other sizes and material of polished balls( such as tungsten and heavy alloy balls ) could be customize