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Magnet Grades

Neodymium Grades

A Neodymium (Rare Earth) magnets Grade (eg: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 magnets pull force. However shape, thickness, operating temperature and proximity to other magnetic material will also impact on the magnets performance. Higher Grade magnets can be applied where space is restricted and the use of a larger more powerful magnet is not possible. Letters after the Grade (N42SH) for instance, refer to heat tolerance, up to 150°C and the temperature at which the magnet will become unoperational. N30EH have the highest heat rating and remain effective at temperatures up to 200°C. AMF Magnets have a range of Neodymium Magnets in various grades from N30 to N52 and with heat tolerances from 80° to 200°C.

Ferrite Material / Grades

At AMF Magnets we use the Chinese factory code and stock low cost, lightweight Ferrite Magnets in Y30 Material/Grade in various shapes and sizes or Y10 isotropic grade. Ferrite magnets have a maximum operating temperature of 250°C, a wide magnetic field and excellent resistance to corrosion and demagnetisation.

Samarium Cobalt Grades

All our Samarium Cobalt Magnets at AMF are disc or cylinder shape and Sm2Co17(2-17) Grade. The alloy compound allows them to maintain their magnetism in temperatures up to 350°C. Even uncoated they have superior resistance to corrosion compared to other magnets.

Alnico Grades

Alnico magnets have the highest operating temperature of all Rare Earth Magnets (up to 500°C). AMF supplies 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)
Neodymium 35-52
SmCo 26 26
Alnico 5/8 5.4
Ferrite 3.4