Machining And Tolerances：
NdFeB magnets are brittle, though not as brittle as the SmCo magnets. Machining operations should be completed before coating or plating, using diamond tools, and coolants must be used in the process to avoid spontaneous combustion of powder. Standard tolerances for NdFeB magnets are +/-.005” for ground dimensions. Close tolerances are also available by abrasive grinding and cutting.

Ceramic (Ferrite) Magnets offer the best value when comparing cost. They are inexpensive, moderate in magnetic strength, and they are easily magnetized in a variety of formats. Ceramic magnets offer good corrosion resistance and generally do not require a coating or plating. Consideration should be given to the grade of alloy when exposing Ceramic magnets to temperature extremes. Ceramic magnets have good resistance to external demagnetization fields because of its high Intrinsic Coercive Force (Hci) . This resistance and low cost makes Ceramic magnets a popular choice for electromechanical applications.

Ceramic magnets are very hard and brittle. Like all magnetic materials, ceramic should not be used as a structural element in a design. Ceramic magnets are particularly prone to cracking when the application involves impacts or flexing. As with most ceramic, the ferrite magnets should not be exposed to heating or cooling rates greater than 200°F per hour.