Ultra precision machining is an abrasive precision machining method that uses fine abrasive stones mounted on a vibrating head to perform micro cutting of the workpiece. The main purpose of ultra precision machining is to reduce the Ra value, up to 0.2 to 0.012 μ m. The shape accuracy can be appropriately improved. Ultra precision machining has a high productivity and is commonly used to process the outer, inner, planar, channel surfaces, and spherical surfaces of crankshafts, rollers, bearing rings, and certain precision parts.