Air Gap - Basically the "external" distance from one pole of the magnet to the other though a non-magnetic material (usually air).
Anisotropic - Materials that have a "preferred" magnetization direction. These materials are typically manufactured in the influence of strong magnetic fields, and can only be magnetized through the preferred axis. Neodymium (Iron Boron) and Samarium Cobalt magnets are anisotropic.
B/H Curve - The result of plotting the value of the magnetic field (H) that is applied against the resultant flux density (B) achieved. This curve describes the qualities of any magnetic material.
BHmax (Maximum Energy Product) - The magnetic field strength at the point of maximum energy product of a magnetic material. The field strength of fully saturated magnetic material measured in Mega Gauss Oersteds, MGOe.
Brmax (Residual Induction) - Also called "Residual Flux Density". It is the magnetic induction remaining in a saturated magnetic material after the magnetizing field has been removed. This is the point at which the hysteresis loop crosses the B axis at zero magnetizing force, and represents the maximum flux output from the given magnet material. By definition, this point occurs at zero air gap, and therefore cannot be seen in practical use of magnet materials.
C.G.S. � Abbreviation for the "Centimeter, Grams, Second" system of measurement.
Coercive Force - The demagnetizing force, measured in Oersteds, necessary to reduce observed induction, B, to zero after the magnet has previously been brought to saturation.
Curie Temperature (Tc) - The temperature at which a magnet loses all of its magnetic properties.
Demagnetization Curve - The second quadrant of the hysteresis loop, generally describing the behavior of magnetic characteristics in actual use. Also known as the B-H Curve.
Demagnetization Force - A magnetizing force, typically in the direction opposite to the force used to magnetize it in the first place. Shock, vibration and temperature can also be demagnetizing forces.
Dimensions - The physical size of a magnet including any plating or coating.
Dimensional Tolerance - An allowance, given as a permissible range, in the nominal dimensions of a finished magnet. The purpose of a tolerance is to specify the allowed leeway for imperfections in manufacturing.
Electromagnet - A magnet consisting of a solenoid with an iron core, which has a magnetic field only during the time of current flow through the solenoid.
Ferromagnetic Material - A material that either is a source of magnetic flux or a conductor of magnetic flux. Any ferromagnetic material must have some component of iron, nickel, or cobalt.
Gauss - Unit of magnetic induction, B. Lines of magnetic flux per square centimeter in the C.G.S. system of measurement. Equivalent to lines per square inch in the English system, and Webers per square meter or Tesla in the S.I. system.
Gauss meter - An instrument used to measure the instantaneous value of magnetic induction, B, usually measured in Gauss (C.G.S.).