A Neodymium (Rare Earth) magnet Grade (for example, N42) is an accurate guide to the strength of a magnet. Generally speaking, higher grade numbers indicate a stronger or more powerful magnet. The number comes from an actual material property, the Maximum Energy Product of the magnet material, expressed in MGOe (Mega Gauss Oersteds). It represents the strongest point on the magnet's Demagnetization Curve, or BH Curve. The pull force of a magnet varies with the grade, or 'N' number. As the Grade increases, so does the magnet's pull force. However, shape, thickness, operating temperature and proximity to other magnetic material will also impact the magnets performance. Higher grade magnets are typically used where space is restricted and it would be difficult or impossible to use a larger, more powerful magnet. Letters after the Grade, for example N42SH, refer to heat tolerance, or the temperature at which the magnet will become unoperational. N30EH have the highest heat rating and remain effective at temperatures up to 392°F or 200°C. AMF Magnets has a range of Neodymium Magnets in various grades from N30 to N52 and with heat tolerances from 176°F to 392°F (80°C to 200°C).
Ceramic / Ferrite
At AMF Magnets we use the Chinese factory code and stock low cost, lightweight Ceramic / Ferrite Magnets in Y30 Material/Grade in various shapes and sizes or Y10 isotropic grade. Ceramic Ferrite magnets have a maximum operating temperature of 482°F (or 250°C), a wide magnetic field and excellent resistance to corrosion and demagnetization.
All our Samarium Cobalt magnets at AMF Magnets are Grade Sm2Co17 (2-17) . The alloy compound allows them to maintain their magnetism in temperatures up to 662°F (or 350°C). Even uncoated they have superior resistance to corrosion compared to other magnets.
Alnico magnets have the highest operating temperature of all Rare Earth Magnets -- up to 932°F (or 500°C). AMF Magnets stocks Alnico magnets in the shape of Blocks, Cylinders, Pots and Horseshoes. They are manufactured using a compound that is highly conductive by either a Casting or Sintering process. We have grades in stock that include Alnico 5 and Alnico 8. You can click on the Technical Specifications / Magnetic Properties of each Alnico product for a table of the Grades.
This table shows the relative strengths of Permanent Magnets.
|Magnet Type||Max Energy Product (MGOe)|