The choice of particle shape of a MAP is determined to a large extent by the hardness of its structural components and by the machinability of the metal to be polished. In the magnetoabrasive polishing of quenched steels and other hard materials, e.g., hard metals, the best results are obtained with a MAP whose particles consist of a ferromagnetic matrix with hard abrasive inclusions and are preferably of round shape. The magnetoabrasive polishing of nonferrous metals and alloys (brass, copper, bronze, and titanium) should be performed with a MAP of sufficiently high integral particle hardness. In this case a round particle shape ensures a higher class of work surface finish, while an angular particle shape results in faster removal of metal.