How to Choose the Right Magnet Material

Define the field or torque requirement, space, operating temperature, reverse field, exposure and assembly. Use those inputs to compare material datasheets and models. Do not select a prototype grade from a generic default.

Sintered NdFeB can provide high energy product per unit volume. Bonded NdFeB has different property and processing options. Mainrich’s sintered NdFeB range is N30 to N56, with no AH grades. The top grade depends on the temperature series: N56, N54M, N52H, N52SH, N50UH and N45EH. Grades up to N52SH can be made without a Chinese export licence, so we offer those first; UH and EH grades need a licence, applied for per order. Confirm the grade, suffix, geometry and production route for each drawing. This summary does not offer every combination; grades outside it in educational examples are not Mainrich supply offers. Permanent-magnet MRI references concern the main-field system of particular scanner designs; gradient coils are electrically driven.

Compare SmCo when thermal stability or environmental conditions justify it. Use the exact grade’s hot curves and corrosion information. No material name establishes a universal temperature limit or medical-device suitability.

Ferrite and Alnico have different remanence, coercivity, thermal behaviour and circuit requirements. Compare the actual grade over the intended temperature range, including the reverse-field condition. A low raw-material cost alone does not determine the installed cost.

Compare measurements in the same circuit and agree the acceptance test. The reported N45H magnetic comparison and the separate historical 50H Dy-reduction example have different scopes. See the GBD evidence and limitations. Finished-part savings require a quotation and qualification of the proposed route.