Process Feature

After a metal piece is ground to an initial finish, it is superfinished with a finer grit abrasive stone. The stone is oscillated or rotated while the workpiece is moved in such a way that each bonded grain of abrasive follows a random path with variations in speed, direction and pressure. This multi-motion is a key feature of superfinishing because it prevents the sort of smeared finish that results from built up edge.

In this way, superfinishing is similar to lapping, but with a bonded abrasive stone rather than loose or embedded abrasive. The geometry of the stone depends on the geometry of the workpiece surface; A lubricant is used to minimize heat production, which can alter the metallurgical properties, and to carry away the swarf.