Neodymium magnets (Nd-Fe-B) are composed of neodymium, iron, boron and a few transition metals. These magnets are extremely strong for their small size, metallic in appearance and found in simple shapes such as rings, blocks and discs,Arc.

Applications of Neodymium
Magnetic separators, linear actuators, microphone assemblies, servo motors, DC motors (automotive starters), computer rigid disc drives, printers and speakers.

Tolerances
For as pressed material, tolerance on the thickness (direction of magnetization) is ? .005. Other dimensions are ? 2.5% or ? .010, whichever is greater. According to IMA standards, visual imperfections such as hairline cracks, porosity and minor chips are commonly found in sintered metallic magnets. A chipped edge is considered acceptable if no more than 10% of the surface is missing. Cracks are acceptable as long as they do not extend across more than 50% of pole surface