Sintered - fine NdFeB powder is compacted in a die and then sintered, fusing the powder into a solid material. There are 2 forms of pressing: die pressing (which involves a hard die into which the powder is placed and then pressed), and isostatic pressing (involving a special "rubber" die into which powder is placed and then pressed with equal force in all directions on the powder). Die pressed parts are usually made smaller than isostatically pressed parts. Although the magnetic properties of isostatically pressed parts are higher, the uniformity of magnetic characteristics is usually lower than that of die pressed parts. Sintered parts normally need some finish machining in order to meet final tolerances.