Honing is an abrasive machining process. It involves the usage of abrasive stones that are held under pressure against the metallic surface that is to be honed. These abrasive stones produce a scrubbing motion and it is guided along the metallic surface in a controlled path, producing a precision surface and improving the geometric form of a surface. It also improves the surface texture/finishing (measured as Ra micrometers or Ra microinches).
With a smoother surface and improved shape, the process of honing metallic components would result in quieter running machines and higher precision instruments. Typical applications are the finishing of cylinders, internal combustion engines, air bearing spindles, gears / tubes for liquids and blow off valves.